Current Radar or Satellite Image

Flhurricane.com - Central Florida Hurricane Center : Hurricanes Without the Hype since 1995


Basin is Uncommonly Quiet With No Development in Sight.
Number of days since last Hurricane Landfall in US: 80 (Arthur) , in Florida: 3255 (8 y 10 m) (Wilma)
None
COMMUNICATION
STORM DATA
CONTENT
FOLLOW US
ADS
Login to remove ads

 


Archives >> 2009 News Talkbacks

Jump to first unread post. Pages: 1 | 2 | 3 | 4 | 5 | 6 | >> (show all)
MikeCAdministrator
Admin


Reged: Sun
Posts: 2956
Loc: Orlando, FL 28.49N 81.47W
Tropical Storm Erika Forms East of the Leeward Islands
      #86614 - Sun Aug 30 2009 07:54 AM

4:50 PM EDT 1 Sep 2009 Update
More to Come soon, but the wave known as 94L has become Tropical Storm Erika.

It is moving West Northwest at 9MPH, and has 50mph winds.

The forecast track has it east of the Bahamas in 120 hours, and after that depends on how strong or weak the system gets. If it gets stronger, it will likely move more north and out to sea, while a weaker system will likely stay more westward.


6:20 AM EDT 1 Sep 2009 Update
The wave east of the Caribbean is looking good on satellite, but is missing the low level circulation it needs to become a tropical cyclone. This morning there are actually signs of that happening, but all the convection and storm energy seems to be the east of it. This is due to persistent shearing in the area keeping it a bit disorganized, which has been common this year. Ie, the low level is doing one thing, while the mid level is doing another.

Martinique Radar

It still has a greater than 50% chance of becoming a depression in the next 48 hours. By 11AM is likely today.

With the weaker system, the more west it goes. Those in the Leeward islands, Virgin Islands, and Puerto Rico will want to continue to watch this system. Models still have not been handling the initialization of the system well. However, the GFDL model, now no longer dissipates the system. Until this gets organized it is impossible to say if it will have any impact on the US or not, again odds are slightly in favor of it staying out to sea. The forecast for this system will likely be more difficult than most.



The other wave east of the Bahamas is mostly an upper level feature, but it has been persistent. But there are currently no signs of a low level move that would allow for development.

In the Pacific, Hurricane Jimena has become a strong Category 4 Hurricane nearing a Category 5, and is expected to landfall in Mexico along the Baja California Peninsula as a Category 3 hurricane .



9:40 AM EDT 31 Aug 2009 Update
There is a better chance this morning that a depression will form from 94L. The overall structure is there, but the convection around the center still lacks (see Dvorak estimates). It looks fairly well this morning so it may become a depression at 11AM. There is some shear ahead of it, which may keep it from organizing, and also the circulation center is not under most of the convection, this may keep it from being upgraded.

The Windward islands of the Caribbean still need to watch 94L closely, and longer range models have bent back further west, which will keep the Bahamas and the southeast US in a monitor mode until it gets closer. Recon aircraft will start to head out there tomorrow.

Odds this year favor systems out to sea, but 94L has a better than usual chance of breaking it and heading more west. We will have to monitor it..

The wave east of the Bahamas (has no invest number) has little low level activity and is not likely to develop soon, it too is worth watching to see if anything changes with it.

Original Update
The wave east of the Caribbean, 94L, has survived the last few days weak, and moved more west. It is now poised to develop today or tomorrow, it has greater than a 50% chance to develop within the next 48 hours.

Most forecast models have had a terrible time with this system, trending it north incorrectly over and over again. It remaining weak and mostly low level has kept it more on a westerly track. If and until this develops, the models will not be of much worth with it. That said, those in the Leeward and Windward Caribbean islands need to watch this system. It may strengthen some then weaken again. There is some shear north of the system, so the further south and west it stays the more chance it has for survival.

If it does develop movement to the northwest and north is more likely, and the odds are that it will not affect the US if it does.



The best course of action is to continue to wait and see what occurs with the system.

Other things to watch include a smaller wave north of the Lesser Antilles, and energy in the Southwestern Caribbean for any persistence.

StormCarib Reports from the Caribbean Islands

Caribbean Weather Observations

Barbados Brohav Weather Fax

Caribbean Broadcast Corporation (TV/Radio from Antilles)

San Juan, PR Radar Long Range Radar Loop ( Latest Static)

Various Caribbean Radio Stations

DR1 Dominican Republic Hurricanes
94L Event Related Links


Animated Skeetobite Model Plot of 94L


stormplotthumb_6.gif

SFWMD Model Plot (Animated Model Plot) SFWMD Hurricane Page
Clark Evans Track Model Plot of 94L (Animated!) Model Plots in Google Earth - In Google Maps
Clark Evans Intensity Model Plot of 94L (Animated!)

Clark Evans Track Plot of 94L

Other Model Charts from Clark

Clark Evans Top 10 Analog Storms for 94L
More model runs on from RAL/Jonathan Vigh's page
NRL Info on 94L -- RAMMB Info

Floater Satellite Images: Visible (Loop), IR (Loop), WV (Loop), Dvorak (Loop), AVN (Loop), RGB (Loop), Rainbow (Loop), Funktop (Loop), RB Top Loop)


Post Extras: Print Post   Remind Me!   Notify Moderator  
craigm
Storm Tracker


Reged: Wed
Posts: 245
Loc: Palm City, Florida 27.17N 80.27W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: MikeC]
      #86616 - Sun Aug 30 2009 08:44 AM

94L held on to all of its convection overnight and now seems to be consolidating.
Discussion out of NWS San Juan up coming week:
000
FXCA62 TJSJ 300829
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
429 AM AST SUN AUG 30 2009

.SYNOPSIS...DEVELOPING TUTT LOW NORTH OF PR WILL DRIFT TO THE SOUTH
SOUTHWEST OVR THE NEXT 48 HRS AND HELP MAINTAIN A WET PATTERN ACROSS
THE REGION OVER THE NEXT COUPLE OF DAYS. TROPICAL WAVE ALONG 45W
WILL TRACK ACROSS THE REGION DURING THE LATTER PART OF THE WORK
WEEK.

&&

.DISCUSSION...WATER VAPOR IMAGERY SHOWS DEVELOPING TUTT LOW NORTH
OF PR EARLY THIS MORNING. THIS FEATURE IS FCST TO DRIFT SOUTH
SOUTHWEST DURING THE NEXT 48 HRS AND SETTLE OVR HISPANIOLA BY MON
EVENING. VEERING WINDS IN THE MID AND UPPER LVLS OF THE ATMOSPHERE WILL
HELP DRAW MOISTURE NWD FROM THE DEEP TROPICS INTO OUR AREA AND
KEEP US WET FOR THE NEXT COUPLE OF DAYS.

FOR TUE-WED AND POSSIBLY INTO THU...GLOBAL MODELS SHOW INCREASING
SUBSIDENCE/DRYING AS HEIGHTS RISE AS MID-UPPER LVL RIDGE ACROSS
THE TROP ATLC BUILDS WESTWARD. HOWEVER...CAP DOES NOT LOOK STRONG
ENOUGH TO COMPLETELY SUPPRESS CONVECTION BUT DO EXPECT A SIG DROP
IN CONVECTIVE CVRG.

THE FORECAST FOR THE END OF THE NEW WORK WEEK WILL BE HIGHLY
DEPENDENT ON THE TRACK/EVOLUTION OF TROPICAL WAVE CURRENTLY ALONG
45W. FIRST IMAGES AFTER THE SATELLITE ECLIPSE SHOW A MARKED
INCREASE IN CONVECTION WITH A CIRCULATION TRYING TO CLOSE OFF NEAR
11.2N AND 45.1W. NOT SURE IF THIS IS THE BEGINNING OF A
INTENSIFICATION PHASE OR A SHORT TERM TREND GIVEN FVRBL CONVECTIVE
UPSWING SEEN WITH TROPICAL SYSTEMS AT NIGHT BUT SYSTEM DEFINITELY
LOOKING MUCH BETTER ORGANIZED THAN 24 HRS AGO. SVRL GLOBAL MODELS
STILL SHOW DEVELOPMENT OF THIS WAVE INTO A TROPICAL CYCLONE DURING
THE NEXT FEW DAYS. THE EUROPEAN MODEL WHICH HAS BEEN THE MOST
RELIABLE/CONSISTENT MODEL THIS YEAR TRACKS THIS SYSTEM VERY CLOSE
TO THE AREA DURING THE LATTER PART OF THE WORK WEEK. IT HAS ALSO
BEEN THE MOST CONSISTENT WITH THIS SYSTEM KEEPING IT SOUTH OF 20N
OVER THE PAST THREE DAYS. MODELS ALSO INDICATE SYSTEM SLOWING
DOWN SIGNIFICANTLY ONCE IT REACHES 55W. GREAT AMOUNT OF
UNCERTAINTY HERE ESPECIALLY WITH RESPECT TO TIMING AND INTENSITY.

--------------------
Why I'm here:
Frances,Jeanne,Wilma,worked on Andrew damage


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hurikid
Verified CFHC User


Reged: Mon
Posts: 14
Loc: Barbados
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: craigm]
      #86617 - Sun Aug 30 2009 08:59 AM

I live in Barbados, and I feel that if continues moving on this heading and intensifies somewhat.....watches and warnings may be required for my area by this evening......and on the weather news last night they barely spent 3 seconds on it stating that it will go north of the entire LESSER ANTILLIES

Post Extras: Print Post   Remind Me!   Notify Moderator  
OrlandoDan
Storm Tracker


Reged: Mon
Posts: 267
Loc: Longwood, FL 28.69N 81.44W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Hurikid]
      #86618 - Sun Aug 30 2009 09:06 AM

94L is definitely looking better organized now. Notice the start of a classic outflow pattern in the NW quadrant.

--------------------
Keith (1988), Charley (2004), Frances (2004) , Jeanne (2004), Fay (2008)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hugh
Senior Storm Chaser


Reged: Fri
Posts: 1060
Loc: Okaloosa County, Florida 30.51N 86.50W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: OrlandoDan]
      #86620 - Sun Aug 30 2009 10:02 AM

what a difference a few hours makes!
Last night, 94L was down to code yellow, and that looked very generous.
Today, the inflow looks excellent and it looks on the verge of becoming a TD.

Speaking of things changing quickly... over in th EPAC.. the "extremely small" Hurricane Jimena has tripled in size this morning, it looks like, and is well on the way to Cat 4+.

Things can change in a hurry this time of year.

--------------------
Hugh

Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Random Chaos
Weather Analyst


Reged: Sat
Posts: 998
Loc: Maryland 38.98N 76.50W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Hugh]
      #86622 - Sun Aug 30 2009 10:13 AM

Based on Quikscat, it looks like it has a closed circulation too, visible in a pass a few hours ago:

http://manati.orbit.nesdis.noaa.gov/storm_at_image21/qscat09083007_94as.png

Not much wind yet, though, but I would expect it to be called a tropical depression later today. The latest quikscat shows max 35kt vectors in questionable locations, and otherwise caps at 20kt:

http://manati.orbit.nesdis.noaa.gov/storm_at_image21/qscat09083013_94as.png

Most models aren't picking up any sort of track yet since they are not developing the storm. CMC, which tends to overdevelop storms, shows a track heading WNW to a spot in about 5 days north of Puerto Rico, but slowing down to almost stopped toward the end of that period. We won't have any really decent track data until about 12 hours after it is a tropical storm, though.

All Quikscat graphics: http://manati.orbit.nesdis.noaa.gov/cgi-bin/qscat_storm.pl


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hugh
Senior Storm Chaser


Reged: Fri
Posts: 1060
Loc: Okaloosa County, Florida 30.51N 86.50W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Random Chaos]
      #86624 - Sun Aug 30 2009 10:37 AM

Graphic on INVEST94 does not load at NRL.... are they in the process of preparing to pull the trigger?

Well it loads now (the satellite image), plus there is a TCFA issued now. So I guess no trigger YET..

--------------------
Hugh

Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)


Edited by Hugh (Sun Aug 30 2009 10:39 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
berrywr
Weather Analyst


Reged: Fri
Posts: 370
Loc: Opelika, AL 32.71N 85.23W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: MikeC]
      #86627 - Sun Aug 30 2009 12:41 PM

That is correct; the shallower 94L is it will be steered by the low level "trade" winds, east to west. Once 94L becomes deeper and more vertical it should begin to gain some latitude. 30/12Z Model package continue to keep a broad longwave trough over the Eastern United States with a cutoff upper low setting up shop over the Mid-Tennesee Valley at H+72 hours and opening back up at H+120 hours but continuing a broad but weaker longwave trough over the east effectively blocking any storm from approaching the coast. This setup also induces Southwest shear once again. All that said, this system is considerably farther south and if the system remains shallow then things become a bit more interesting; stay tune.

--------------------
Sincerely,

Bill Berry

"To work in the service of life and the living..." - John Denver


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Hugh]
      #86629 - Sun Aug 30 2009 12:50 PM

Seems to be a bit of disparity among the computers. The NHC graphic for 94L indicates a Code RED.
While this morning Tropical Discussion puts 94L in the 30-50% group, or Medium chance of becoming a tropical cyclone in the next 48 hours.

AN ATLANTIC OCEAN TROPICAL WAVE GOES FROM 16N42W TO A 1009 MB
LOW PRESSURE CENTER NEAR 11N44W TO 7N49W MOVING WEST 15 TO 20 KT.
STRONG SHOWERS AND THUNDERSTORMS ARE FROM 10N TO 13N BETWEEN
45W AND 48W. ISOLATED MODERATE SHOWERS TO LOCALLY STRONG
THUNDERSTORMS ARE ELSEWHERE FROM 10N TO 17N BETWEEN 40W AND
50W...AND FROM 7N TO 11N BETWEEN 50W AND 57W IN WHAT APPEARS
TO BE POSSIBLY ITCZ PRECIPITATION THAT IS BEING ENHANCED AND/OR
PUSHED NORTHWARD BY THE LOW CENTER/TROPICAL WAVE SYSTEM. THE
CHANCE FOR THIS SYSTEM TO BECOME A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS IS MEDIUM.
http://www.nhc.noaa.gov/text/refresh/MIATWDAT+shtml/301130.shtml?

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT SUN AUG 30 2009

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

CLOUDINESS AND SHOWERS ASSOCIATED WITH A BROAD AREA OF LOW PRESSURE
LOCATED ABOUT 950 MILES EAST OF THE WINDWARD ISLANDS CONTINUE TO
BECOME BETTER ORGANIZED. THIS SYSTEM COULD BECOME A TROPICAL
DEPRESSION DURING THE NEXT DAY OR SO AS IT MOVES WEST-NORTHWESTWARD
AROUND 15 MPH. THERE IS A HIGH CHANCE...GREATER THAN 50
PERCENT...OF TROPICAL CYCLONE FORMATION IN THIS AREA DURING THE
NEXT 48 HOURS. INTERESTS IN THE LESSER ANTILLES SHOULD MONITOR THE
PROGRESS OF THIS SYSTEM.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
http://www.nhc.noaa.gov/text/refresh/MIATWOAT+shtml/301133.shtml


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: berrywr]
      #86630 - Sun Aug 30 2009 12:56 PM

Wonder if any of the models are picking up on the recurvature of E Pac Hurricane Jimena recurving into the Desert Southwest in a few days. That could throw a wrench into the current ridge in place... and put out a few fires. But the tropical moisture could also bring mudslides.

A bit of a stretch from the Atlantic Basin discussion here but certainly food for thought.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hugh
Senior Storm Chaser


Reged: Fri
Posts: 1060
Loc: Okaloosa County, Florida 30.51N 86.50W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: danielw]
      #86631 - Sun Aug 30 2009 01:03 PM

Quote:

Wonder if any of the models are picking up on the recurvature of E Pac Hurricane Jimena recurving into the Desert Southwest in a few days. That could throw a wrench into the current ridge in place... and put out a few fires. But the tropical moisture could also bring mudslides.
A bit of a stretch from the Atlantic Basin discussion here but certainly food for thought.




I had not thought of that. It's certainly something that the models do seem to be leaning towards with Jimena. I'm not sure the moisture would have a big impact on the Atlantic basin, though.

--------------------
Hugh

Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)


Post Extras: Print Post   Remind Me!   Notify Moderator  
hogrunr
Weather Guru


Reged: Sun
Posts: 153
Loc: Spring, TX 30.07N 95.51W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Hugh]
      #86634 - Sun Aug 30 2009 02:33 PM

Am I just imagining things....or is there another wave that looks like it could flare up fairly quickly just north of the Antilles?


http://www.ssd.noaa.gov/goes/east/catl/loop-rb.html


Post Extras: Print Post   Remind Me!   Notify Moderator  
Beach
Weather Guru


Reged: Wed
Posts: 187
Loc: Cocoa Beach/Banana River
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: hogrunr]
      #86635 - Sun Aug 30 2009 02:41 PM

OH BOY !
Looking at the visible loop, it sure looks like 94L is getting it's form together this afternoon.

http://www.ssd.noaa.gov/goes/east/tatl/loop-vis.html


Post Extras: Print Post   Remind Me!   Notify Moderator  
Random Chaos
Weather Analyst


Reged: Sat
Posts: 998
Loc: Maryland 38.98N 76.50W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: hogrunr]
      #86636 - Sun Aug 30 2009 02:48 PM

I assume you are asking about the rotating convection near 60-65W 20-25N? That is the extension of the frontal system that absorbed Danny. It is possible that it could become cut off, but right now it is not. You can tell this via the Water Vapor loop:

http://www.ssd.noaa.gov/goes/east/natl/loop-wv.html

I'm actually a little more interested in what is going on down around 80W 10-15N. There is also a tropical wave to the east of that - around 70W. The way the convection is acting, it isn't typical of thunderstorms. Nothing tropical yet, though.

NHC only has Invest 94L active - that is the system around 50W 10N.


Post Extras: Print Post   Remind Me!   Notify Moderator  
ftlaudbob
Storm Chaser


Reged: Tue
Posts: 757
Loc: Lauderdale-By- the- Sea,Fl 26.19N 80.10W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Random Chaos]
      #86637 - Sun Aug 30 2009 03:15 PM

Looking at this loop http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html I believe 94L may become Erica late tonight or tomorrow .

--------------------

Survived:
Gloria,Bob,Katrina,Wilma and a bunch of tropical storms.


Post Extras: Print Post   Remind Me!   Notify Moderator  
hogrunr
Weather Guru


Reged: Sun
Posts: 153
Loc: Spring, TX 30.07N 95.51W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Random Chaos]
      #86639 - Sun Aug 30 2009 03:48 PM

Quote:

I assume you are asking about the rotating convection near 60-65W 20-25N? That is the extension of the frontal system that absorbed Danny. It is possible that it could become cut off, but right now it is not. You can tell this via the Water Vapor loop:

http://www.ssd.noaa.gov/goes/east/natl/loop-wv.html

I'm actually a little more interested in what is going on down around 80W 10-15N. There is also a tropical wave to the east of that - around 70W. The way the convection is acting, it isn't typical of thunderstorms. Nothing tropical yet, though.

NHC only has Invest 94L active - that is the system around 50W 10N.




Yes that exactly which one I am referring too, I see where it is connected now, so it will just require some further watching for now.

I also saw the system earlier at 80W that you are referring to, most of the systems in that area have been just moving inland over Central America, but this one looks like it might take a NNW route out of that area and that would put it awfully close to home. There is really nothing out there to stop it.


Post Extras: Print Post   Remind Me!   Notify Moderator  
JMII
Weather Guru


Reged: Thu
Posts: 161
Loc: Margate, Florida 26.26N 80.22W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: rgd]
      #86641 - Sun Aug 30 2009 04:47 PM

94L looks pretty good. It doesn't have a real core yet, but has good outflow on all sides except some shear to the WSW. Its a little squished and not very round/symmetrical, yet still looks more organized then some of the weaker storms we've seen so far this year.

--------------------
South FL Native... experienced:
David ('79) - Floyd ('87) - Andrew ('92) - Georges ('98) - Irene ('99) - Frances & Jeanne ('04) - Katrina & Wilma ('05)


Post Extras: Print Post   Remind Me!   Notify Moderator  
AdvAutoBob
Weather Watcher


Reged: Wed
Posts: 35
Loc: Cape Coral, FL 26.63N 81.95W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: JMII]
      #86642 - Sun Aug 30 2009 05:50 PM

94L is definitely trying to get its act together... Still looks a mess to me, maybe TD by morning, but hardly Erica (yet).. the media has been ramping up for some kind of natural disaster, and it's my hope this one's a bust as well (or a fish)

--------------------
"Chance favors the prepared mind"


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ed DunhamAdministrator
Meteorologist & CFHC Forum Moderator


Reged: Sun
Posts: 2309
Loc: Melbourne, FL
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: MikeC]
      #86644 - Sun Aug 30 2009 06:39 PM

Just a reminder that posts on the Main Page thread and the Storm Forum are still moderated more diligently. Stick to the site rules, stay on topic, and don't get flippant or abusive to others. If your post is no longer visible, thats probably the reasons why.
ED


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
Watch the back door again...GOM [Re: Ed Dunham]
      #86645 - Sun Aug 30 2009 07:55 PM

Excerpt from the afternoon AFD at NWS Slidell,LA

.LONG TERM...

HEADING INTO THE MIDDLE OF THE WEEK...ONE FEATURE TO BE NOTICED
IS THE DEVELOPMENT OF A POSSIBLE LOW ALONG THE OLD FRONTAL
BOUNDARY IN THE CENTRAL GULF OF MEXICO WEDNESDAY INTO THURSDAY.
BOTH THE NAM AND GFS DEPICT A WEAK SURFACE LOW FORMING...AND THEN
SLOWLY MOVING TO THE NORTHEAST TOWARD THE FLORIDA PANHANDLE. GIVEN
THE TIME OF YEAR...THERE MAY BE SOME POTENTIAL FOR A WEAK TROPICAL
LOW TO TAKE HOLD. HOWEVER...SEVERAL LIMITING FACTORS WILL BE IN
PLAY...INCLUDING DRY AIR FEEDING INTO THE SYSTEM AND A DECENT
AMOUNT OF SHEAR IN THE REGION. FORTUNATELY...THE REGION LOOKS TO
BE ON THE WESTERN OR DRIER SIDE OF THE SYSTEM FOR THE LATTER HALF
OF THE WEEK. AT MOST...SOME WRAP AROUND MOSITURE AND SHOWERS MAY
AFFECT COASTAL MISSISSIPPI ZONES ON THURSDAY.
http://flhurricane.com/text/AFDLIX.txt

Worth keeping an eye on.
Late Sunday afternoon there was a confirmed tornado in Corpus Christi,TX. Which is near the southern end of the frontal boundary.


Post Extras: Print Post   Remind Me!   Notify Moderator  
weathernet
Storm Tracker


Reged: Sat
Posts: 296
Loc: Elsewhere 80.30N 50.63E
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Ed Dunham]
      #86646 - Sun Aug 30 2009 08:42 PM

Wave east of the Lesser Antilles is really a nice sized envelope system. Looks to have a significant mid level rotation, thus the overall model consensus wiht a WNW to NW bias. Best chances for development would appear if the system does lift more poleward, and fortunately would appear to lessen any eventual threat to the U.S. if given such motion. The system itself has really looked to be on the verge, yet seems to be "vertically challanged", given the 200mb 30kt/40kt southerly winds on its western flank.

It is this shear itself, along with a mid level flow attempting to move this system more poleward, verses a low level flow which has continued to push the overall system more westward, which I believe may all in tandum be an overall effect of snatching away any consistant convection from maintaining itself. I cannot see any development in the short term, if this system somehow continues to move with the lower level flow.


Post Extras: Print Post   Remind Me!   Notify Moderator  
JoshuaK
Weather Guru


Reged: Mon
Posts: 138
Loc: Central Florida 28.12N 81.99W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: weathernet]
      #86648 - Mon Aug 31 2009 05:17 AM

Big blow up of strong convection over the low level circulation area. Could have a TD in the works, if it persists.

Post Extras: Print Post   Remind Me!   Notify Moderator  
ncskywarn
Registered User


Reged: Mon
Posts: 5
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: JoshuaK]
      #86649 - Mon Aug 31 2009 05:33 AM

It looks like 94l may finally be trying to get its act together lets see if the convection persists or even expands over the circulation center as opposed to just pulse (even though to me it looks more impressive then it has the last couple of days with the convection close to the circulation center) . If it can maintain it thru-out the day my guess is the NHC will start initiating advisories at 5 PM.

--------------------
Certified Skywarn Spotter


Post Extras: Print Post   Remind Me!   Notify Moderator  
berrywr
Weather Analyst


Reged: Fri
Posts: 370
Loc: Opelika, AL 32.71N 85.23W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: weathernet]
      #86650 - Mon Aug 31 2009 05:49 AM

31/00Z package has an upper low north of Puerto Rico showing up quite nicely from 500mb to 200 mb with an inverted trough at 700 mb. The upper Bermuda ridge north and east of Bermuda with a ridge axis extending southwestward to Cuba and the pesky longwave trough once again making its presence known across the Eastern United States. SSEC Wind Shear analysis confirms upper low and upper ridge to its north presenting 94L with a hostile environment immediately to its northwest so while for the moment 94L looks quite ready to be classified a depression, unless the low shear environment that lies just above the system travels with it; it's going to be a tough go to sustain any kind of vertical development given the velocity of those winds aloft at this time. Overall upper pattern continues to put a cessation of any approach to the US at this time. Only threat to US is if this system remains shallow and upper trough over east retreats and fills over time and is replaced with upper ridge as some models are hinting. For the moment, upstairs is not a good place for tropical cyclones.


Edited by Ed Dunham (Mon Aug 31 2009 08:37 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
94L [Re: berrywr]
      #86652 - Mon Aug 31 2009 07:24 AM

Shouldn't be too long before we see an update on 94L. Appearance of a CDO like structure and banding would up the Dvorak numbers a bit. Earlier IR2 shortwave revealed a moderate amount of lightning in the CDO area.

31/0615 UTC 14.1N 49.5W T1.0/1.5 94L -- Atlantic

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT MON AUG 31 2009

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A BROAD AREA OF LOW
PRESSURE LOCATED ABOUT 600 MILES EAST OF THE LESSER ANTILLES HAVE
BECOME BETTER ORGANIZED THIS MORNING. THIS SYSTEM COULD BECOME A
TROPICAL DEPRESSION DURING THE NEXT DAY OR SO AS IT MOVES
WEST-NORTHWESTWARD AT AROUND 15 MPH. THERE IS A HIGH
CHANCE...GREATER THAN 50 PERCENT...OF TROPICAL CYCLONE FORMATION IN
THIS AREA DURING THE NEXT 48 HOURS. INTERESTS IN THE LESSER
ANTILLES SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.


Edited by danielw (Mon Aug 31 2009 07:43 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
Re: 94L [Re: danielw]
      #86653 - Mon Aug 31 2009 08:02 AM

Using this link and allowing for the satellite eclipse. Current motion of the convective hot tower in the CDO area is about 300 to 310 degrees or WNW.
http://www.ssd.noaa.gov/goes/flt/t2/loop-wv.html
Current motion Should take the system along the Northern Edge of the Lesser Antilles. Again that's Should take the system...
Please refer to Official NHC Forecasts, Watches and Warnings and local Statements from Island Officials.

Latest Dvorak... up 0.5.
31/1145 UTC 15.2N 51.5W T1.5/1.5 94L -- Atlantic
edited at 0925 EDT

Edited by danielw (Mon Aug 31 2009 09:26 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
hogrunr
Weather Guru


Reged: Sun
Posts: 153
Loc: Spring, TX 30.07N 95.51W
Re: 94L [Re: danielw]
      #86654 - Mon Aug 31 2009 09:34 AM

Quote:

Using this link and allowing for the satellite eclipse. Current motion of the convective hot tower in the CDO area is about 300 to 310 degrees or WNW.
http://www.ssd.noaa.gov/goes/flt/t2/loop-wv.html
Current motion Should take the system along the Northern Edge of the Lesser Antilles. Again that's Should take the system...
Please refer to Official NHC Forecasts, Watches and Warnings and local Statements from Island Officials.

Latest Dvorak... up 0.5.
31/1145 UTC 15.2N 51.5W T1.5/1.5 94L -- Atlantic
edited at 0925 EDT




daniel....I agree that the initial motion is about 300 degrees, but right about the time the system hits 50W 15N on the map, it then begins to travel due west again along 15N. This of course, is just focusing on the convective center for now. It seems the motion is going to remain fairly wobbly for the time being, but I think most of the models are picking up on some new features to the north of the system and have it turning mostly due west after reaching the northern edge of the lesser antilles. This of course is assuming the models have picked up on enough of the new developments in the system.


Post Extras: Print Post   Remind Me!   Notify Moderator  
metwannabe
Weather Hobbyist


Reged: Wed
Posts: 92
Loc: NC 36.34N 77.73W
Re: 94L [Re: hogrunr]
      #86656 - Mon Aug 31 2009 09:55 AM

Obviously I am no expert here, but any reason NHC will not start issuing advisories at 11 am? In fact I would think that if the "cdo" maintains it may jump straight to TS Erika. Any thoughts?

--------------------
Fran, Bertha, Dennis & Floyd (Tag Team)
Hurricane Season 2010: 15/8/4


Post Extras: Print Post   Remind Me!   Notify Moderator  
hogrunr
Weather Guru


Reged: Sun
Posts: 153
Loc: Spring, TX 30.07N 95.51W
Re: 94L [Re: metwannabe]
      #86657 - Mon Aug 31 2009 09:59 AM

Quote:

Obviously I am no expert here, but any reason NHC will not start issuing advisories at 11 am? In fact I would think that if the "cdo" maintains it may jump straight to TS Erika. Any thoughts?




With the new explosion of convection I would also assume that the 11 am or 2pm would start advisories.

(Off-topic material removed.)

Edited by Ed Dunham (Mon Aug 31 2009 10:06 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
weathernet
Storm Tracker


Reged: Sat
Posts: 296
Loc: Elsewhere 80.30N 50.63E
Re: 94L [Re: hogrunr]
      #86658 - Mon Aug 31 2009 10:07 AM

Though the current bursting trend is certainly impressive, I have not yet seen any bouy or ship obs. which have indicated any falling pressures this morning in the vicinity of 94L. If such a bursting pattern were to exist, then such surface convergence would seem to have to force falling pressures at some point. The upper air is no doubt less than perfect, but perhaps this significantly sized envelope system can some how fight it off. Though I have not checked, I have to believe that recon must be poised to investigate by early tomorrow.

Keep in mind that while some model adjustments ( especially the deep layer BAM and EURO ) have 94L bending back more westward with time, that such an element of longer term positon is also based on the current observation and near term forecast by current global models that 94L remains a shallow and weak system. If in fact 94L can continue to fight off the present upper level shear, than it may attain a bit more latitude in the near term, and thus the more reliable models will not only have a better handle on it, but will possibly cause the initialization of the system, at a point perhaps a little farther north. Beyond that, it is interesting how over time,the Euro certainly does build the longer term heights over the Western Atlantic and E. CONUS. Will have to wait and see if the next couple of runs continue to indicate such a pattern change.

:?:


Post Extras: Print Post   Remind Me!   Notify Moderator  
Evan Johnson
Weather Guru


Reged: Fri
Posts: 143
Loc: Loxahatchee, FL 26.79N 80.28W
Re: 94L [Re: hogrunr]
      #86659 - Mon Aug 31 2009 10:08 AM

right i would venture to say the jump right to a TS might be the case as well. it has bursted with convenction, and looks very organized. still moving westward into warmer waters.

Post Extras: Print Post   Remind Me!   Notify Moderator  
scottsvb
Weather Master


Reged: Mon
Posts: 1096
Loc: fl
Re: 94L [Re: Evan Johnson]
      #86660 - Mon Aug 31 2009 10:21 AM

Nope.....there is no NW winds near the center... there are some to the west but right now..this is more of a ENE-WSW elongated center... like Danny was @ first.

Post Extras: Print Post   Remind Me!   Notify Moderator  
hogrunr
Weather Guru


Reged: Sun
Posts: 153
Loc: Spring, TX 30.07N 95.51W
Re: 94L [Re: weathernet]
      #86661 - Mon Aug 31 2009 10:23 AM

Quote:

Though the current bursting trend is certainly impressive, I have not yet seen any bouy or ship obs. which have indicated any falling pressures this morning in the vicinity of 94L. If such a bursting pattern were to exist, then such surface convergence would seem to have to force falling pressures at some point. The upper air is no doubt less than perfect, but perhaps this significantly sized envelope system can some how fight it off. Though I have not checked, I have to believe that recon must be poised to investigate by early tomorrow.

Keep in mind that while some model adjustments ( especially the deep layer BAM and EURO ) have 94L bending back more westward with time, that such an element of longer term positon is also based on the current observation and near term forecast by current global models that 94L remains a shallow and weak system. If in fact 94L can continue to fight off the present upper level shear, than it may attain a bit more latitude in the near term, and thus the more reliable models will not only have a better handle on it, but will possibly cause the initialization of the system, at a point perhaps a little farther north. Beyond that, it is interesting how over time,the Euro certainly does build the longer term heights over the Western Atlantic and E. CONUS. Will have to wait and see if the next couple of runs continue to indicate such a pattern change.

:?:




If I remember right, there has been a slight drop in pressure, was 1010mb yesterday evening and is now being reported as 1007mb.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ed DunhamAdministrator
Meteorologist & CFHC Forum Moderator


Reged: Sun
Posts: 2309
Loc: Melbourne, FL
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: MikeC]
      #86662 - Mon Aug 31 2009 10:27 AM

The NHC might take the system to TD status at 15Z, but I doubt it. The convection is all to the east of the center. The center itself is roughly at 15N 53W at 31/14Z moving to the west northwest. Since the convection is removed from the actual center, its not really a 'cdo', i.e., the system is still quite disorganized.

Be patient - it will evolve, but just a bit more slowly. It has a rough shear environment ahead of it so intensification will probably be on the slow side. Finally, keep it 'civil' - NHC seems to have a pretty good handle on this one.
Thanks,
ED


Post Extras: Print Post   Remind Me!   Notify Moderator  
cieldumort
Moderator


Reged: Mon
Posts: 1089
Loc: Texas 30.40N 97.80W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: MikeC]
      #86664 - Mon Aug 31 2009 11:18 AM

Fairly confident that 94L actually still consists of two LLCs at present - this is borne out in the most recent scateromter passes from very late last night, and the nearest buoy data that suggests a NNE component to the wind well to the SW of the deepest convection. What has been sorely missing is any buoy or ship data within the deep convection. Windscat however strongly suggests that a far more well-defined LLC is taking shape mostly within that deep convection, not outside of it. This is also backed up by most of the deepest-piercing microwave imagery, that hints of a more dominant LLC near 15.3N 51.5W this morning, than any other location being estimated and tracked. There is almost no question in my own mind that 94L is already a tropical cyclone, that this more central and more co-located LLC has probably won the battle, and that baring any sudden weakening phase, advisories will be started very soon. By tomorrow we might hope for some better model data, but in the meantime it seems reasonable to toss out the bulk of the plots which were tracking a weaker system with a LLC a fair bit south of where the (now dominant, co-located LLC) actually is. This leaves those that fit best with the current extrapolated motion, roughly WNW to NW. These few all tend to cluster around a trip toward the southeast coast, but leave plenty of question as to timing, not to speak of degree of certainty of any possible recurvature back out to sea. Most likely it is now time for Floridians and those in the Antilles and elsewhere to begin keeping a very close eye, and making plans or changes to plans, as necessary.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Tazmanian93
Weather Master


Reged: Sun
Posts: 439
Loc: Tampa
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Ed Dunham]
      #86665 - Mon Aug 31 2009 11:43 AM

Good morning Ed / All... Just curious, is there anything to make of the system just East of the Turks and Caicos? Have not really looked at it yet

--------------------
Don't knock the weather; nine-tenths of the people couldn't start a conversation if it didn't change once in a while.

Go Bucs!!!!!!!!!

****************

Ed


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ed in Va
Weather Master


Reged: Fri
Posts: 489
Loc: 36.02N 75.67W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Tazmanian93]
      #86666 - Mon Aug 31 2009 11:55 AM

I guess the NHC does think much of it, as it doesn't even show on the 11:00 graphic for possible development. Kind of surprising that it didn't, given the proximity to the U.S.

--------------------
Survived Carol and Edna '54 in Maine. Guess this kind of dates me!


Post Extras: Print Post   Remind Me!   Notify Moderator  
cieldumort
Moderator


Reged: Mon
Posts: 1089
Loc: Texas 30.40N 97.80W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Ed in Va]
      #86667 - Mon Aug 31 2009 12:02 PM

The convection east of the Turks & Caicos is related to a ULL, and is not doing much at the surface. For a TUTT low to have any real chance to develop into a named system, it typically takes interaction with a potent tropical wave, or other such catalyst, and even then tropical cyclogenesis rarely occurs... so all that said, some slow development is a tiny bit possible.

Post Extras: Print Post   Remind Me!   Notify Moderator  
WeatherNut
Weather Master


Reged: Wed
Posts: 412
Loc: Atlanta, GA 33.81N 84.34W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: cieldumort]
      #86668 - Mon Aug 31 2009 12:24 PM

I agree that there seem to be 2 LLC's. The inflow patterns are increasingly feeding into the center to the ENE. In fact it looks like some that are visible go right by the front running one directly to the dominant one back behind

--------------------
Born into Cleo (64)...been stuck on em ever since


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Ed Dunham]
      #86669 - Mon Aug 31 2009 12:24 PM

Can we call 94L a double football pattern?
LLC is football shaped and on an east to west axis.
Mid and Upper Level is a bit more rounded but on a north south axis.
Yet another tilted storm.


Post Extras: Print Post   Remind Me!   Notify Moderator  
cieldumort
Moderator


Reged: Mon
Posts: 1089
Loc: Texas 30.40N 97.80W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: MikeC]
      #86670 - Mon Aug 31 2009 01:41 PM

Just a footnote on 94L, AF304 is currently en route to the system, *for tomorrow's tasked mission. Not known to me whether they will venture a detour into the system today, in fact.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Ed DunhamAdministrator
Meteorologist & CFHC Forum Moderator


Reged: Sun
Posts: 2309
Loc: Melbourne, FL
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Tazmanian93]
      #86671 - Mon Aug 31 2009 01:45 PM

As noted by cieldumort, this convection is related to a somewhat smaller upper level low that has been moving generally westward over the past couple of days. If you use a little imagination there might be a weak circulation near 22.7N 70.4W at 31/17Z. Perhaps a code yellow area at 18Z - or perhaps not. The Bermuda extention of the Atlantic ridge appears to be nudging slowly westward.
ED


Post Extras: Print Post   Remind Me!   Notify Moderator  
craigm
Storm Tracker


Reged: Wed
Posts: 245
Loc: Palm City, Florida 27.17N 80.27W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Ed Dunham]
      #86672 - Mon Aug 31 2009 02:43 PM

Playing with the microwave imaging it appears 37 ghz has the best handle on potential COC.

Word of advice, don't link to time sensitive polar satellite images they only refresh every 6 hours and the pass is narrow

--------------------
Why I'm here:
Frances,Jeanne,Wilma,worked on Andrew damage

Edited by craigm (Mon Aug 31 2009 04:22 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
doug
Weather Analyst


Reged: Mon
Posts: 832
Loc: parrish,fl 27.53N 82.44W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: craigm]
      #86677 - Mon Aug 31 2009 04:36 PM

94L looks very sheared to me and it it hard to see any closed circulation. Not ready for prime time yet, I would say.

--------------------
doug


Post Extras: Print Post   Remind Me!   Notify Moderator  
Beach
Weather Guru


Reged: Wed
Posts: 187
Loc: Cocoa Beach/Banana River
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: doug]
      #86678 - Mon Aug 31 2009 06:37 PM

Here is the closest bouy data:

Wind Direction (WDIR): SSW ( 210 deg true )
Wind Speed (WSPD): 17.5 kts
Wind Gust (GST): 21.4 kts
Wave Height (WVHT): 7.5 ft
Dominant Wave Period (DPD): 9 sec
Average Period (APD): 5.4 sec
Atmospheric Pressure (PRES): 29.81 in
Pressure Tendency (PTDY): +0.03 in ( Rising
http://www.ndbc.noaa.gov/station_page.php?station=41040

because there was a westerly wind blowing a while does that mean the low is trying to close off ??
If you read down the page, it looks like there was wind from the west for about 3 hours.

I also wanted to add that if you look at Dvorak Color Infrared Loop: http://www.ssd.noaa.gov/goes/flt/t2/loop-bd.html

It looks like 94L is starting to have a Northerly motion. Possibly interacting with the two Lls infront and ontop of it ??

Edited by Beach (Mon Aug 31 2009 06:41 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
SeaMule
Weather Hobbyist


Reged: Wed
Posts: 64
Loc: Fairhope, Al...on the coast
looking impressive [Re: craigm]
      #86679 - Mon Aug 31 2009 08:27 PM

It sure has nice outflow already, and it's not sucking in dry air from any quadrant. Additionally, I see a comma shape development of deep convection.

I don't see anything to determine a general motion. Perhaps wnw....perhaps almost due west.

what say the mets? Is this a player? LOOKS LIKE IT TO ME....


Post Extras: Print Post   Remind Me!   Notify Moderator  
Evan Johnson
Weather Guru


Reged: Fri
Posts: 143
Loc: Loxahatchee, FL 26.79N 80.28W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Beach]
      #86680 - Mon Aug 31 2009 08:45 PM

interesting to note the navy/nrl track. they are saying its moving northwest, when the NHC is saying west northwest. am i missing something?

nrl track

their discussion...

WTNT01 KNGU 311201
SUBJ/TROPICAL CYCLONE FORMATION ALERT 311201Z AUG 09//
REF/A/MSG/NAVMARFCSTCEN NORFOLK VA/301201Z AUG 09//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTNT01 KNGU 301201)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 14.4N 51.0W TO 16.9N 55.7W
WITHIN THE NEXT 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 25 TO 30 KNOTS. METSAT IM-
AGERY AT 310600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 14.4N 51.0W. THE SYSTEM IS MOVING NORTHWESTWARD AT 13
KNOTS.
2. REMARKS:
THIS SUPERSEDES REF A.
AT 31/06Z INFRARED SATELLITE IMAGERY INDICATED A BROAD
LOW-LEVEL CIRCULATION LOCATED NEAR 14.4N 51.0W TRACKING
NORTHWESTWARD AT 13 KTS. THIS LOW-LEVEL CIRCULATION IS
LOCATED OVER WARM SEA SURFACE TEMPERATURES OF 27 TO 29
DEGREES CELSIUS. UPPER LEVEL WINDS OVER THE SYSTEM ARE SOUTHERLY
25 TO 30 KTS. AS THIS SYSTEM CONTINUES TO TRACK NORTHWESTWARD,
UPPER-LEVEL WIND SHEAR DECREASES PRODUCING CONDITIONS THAT ARE MORE
CONDUCIVE FOR TROPICAL CYCLONE DEVELOPMENT.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 011201Z.//


Post Extras: Print Post   Remind Me!   Notify Moderator  
cieldumort
Moderator


Reged: Mon
Posts: 1089
Loc: Texas 30.40N 97.80W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: Evan Johnson]
      #86681 - Mon Aug 31 2009 09:54 PM

For starters, you have to check the times of all issued advisories, be they ATCFAs or STDS, or anything else.

Also, tracking estimates seem likely to remain pretty unsteady with 94L until we get either a recon in there, or something resembling the starting of an eyewall. It has been a bit of an elongated system with two believable cocs.. and one of the few instances where many may strongly differ in opinion with the official word from NHC - I'm largely in the it-could-have-been designated many hours ago camp, and suspect a more dominant center has actually been forming and is closer to 16N 55W, more co-located with the deep convection, and heading NW. The fact is, we have had no buoy or ship data from within 90 miles of that location in over twelve hours. None. Most of the microwave passes have been partial, at best. And traditional IR satellite is almost useless in a situation like this. It is critical that recon gets in there as soon as possible to determine if in fact a tiny, compact circulation does exist in that region. Until then, we're all best-guessing.


Post Extras: Print Post   Remind Me!   Notify Moderator  
LoisCane
Veteran Storm Chaser


Reged: Fri
Posts: 1212
Loc: South Florida
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: cieldumort]
      #86682 - Mon Aug 31 2009 11:15 PM

Well put Ciel.. very well put. A true problem, especially if a second center is forming. Surprising that there have been no ship reports, for some reason you'd think there would be some. You bring up a lot of good points.

Also been rereading discussion from NRL and looking at it... depends on where the center is as to how far from the islands it is.

Shows nicely on funktop and water vapor as well as having a nice roll to it..

Funktop is green and Dvorak is very solid

http://www.ssd.noaa.gov/goes/flt/t2/loop-bd.html

--------------------
http://hurricaneharbor.blogspot.com/


Post Extras: Print Post   Remind Me!   Notify Moderator  
JoshuaK
Weather Guru


Reged: Mon
Posts: 138
Loc: Central Florida 28.12N 81.99W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: LoisCane]
      #86683 - Tue Sep 01 2009 01:34 AM

94L seems to be undergoing rapid intesification, IMO, based on a number of satellite loops. A big cluster of convection has fired up over what appears to be a circulation center, can't tell if it's low level yet or not, but very good outflow is now beginning, and I'm starting to find it difficult not to classify it as a Tropical Depression at the very least, due to the dangers that such a well organized wave or better would present to maritime shipping, among other things.

Post Extras: Print Post   Remind Me!   Notify Moderator  
blue flash
Registered User


Reged: Thu
Posts: 4
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: JoshuaK]
      #86684 - Tue Sep 01 2009 01:48 AM

Agreed....expect we skip by the TD stage, expect tropical storm advisory at next update.

Post Extras: Print Post   Remind Me!   Notify Moderator  
flanewscameraman
Weather Watcher


Reged: Fri
Posts: 32
Loc: Palm Beach County, FLA
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: blue flash]
      #86685 - Tue Sep 01 2009 01:51 AM

By all appearances, 94L has organized...Let me know your thoughts..

Post Extras: Print Post   Remind Me!   Notify Moderator  
ncskywarn
Registered User


Reged: Mon
Posts: 5
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: flanewscameraman]
      #86686 - Tue Sep 01 2009 01:53 AM

000
ABNT20 KNHC 010535
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT TUE SEP 1 2009

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A BROAD AREA OF LOW PRESSURE LOCATED ABOUT 350 MILES EAST OF THE
LEEWARD ISLANDS CONTINUES TO SHOW SIGNS OF ORGANIZATION...BUT IT
STILL DOES NOT APPEAR TO HAVE A WELL-DEFINED SURFACE CIRCULATION
CENTER. HOWEVER...SATELLITE DATA INDICATE THAT THE SYSTEM IS
PRODUCING WINDS TO NEAR GALE FORCE IN THE ASSOCIATED SHOWER AND
THUNDERSTORM ACTIVITY. THIS SYSTEM COULD BECOME A TROPICAL
DEPRESSION OR TROPICAL STORM AT ANY TIME OVER THE NEXT COUPLE OF
DAYS AS IT MOVES WEST-NORTHWESTWARD AT AROUND 10 MPH. THERE IS A
HIGH CHANCE...GREATER THAN 50 PERCENT...OF TROPICAL CYCLONE
FORMATION IN THIS AREA DURING THE NEXT 48 HOURS. INTERESTS IN THE
LEEWARD ISLANDS...THE U.S. AND BRITISH VIRGIN ISLANDS...AND PUERTO
RICO SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BERG

My guess is the NHC is going to wait until an aircraft investigates 94L this afternoon to see if they can find a LLCC before initiating advisories.

--------------------
Certified Skywarn Spotter


Post Extras: Print Post   Remind Me!   Notify Moderator  
hurricane expert
Really Not an Expert


Reged: Thu
Posts: 105
Loc: florida
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: MikeC]
      #86687 - Tue Sep 01 2009 01:56 AM

IMO this is the best I seen it look. Its starting to get its act together as of now.

http://www.ssd.noaa.gov/goes/flt/t2/flash-wv.html


Post Extras: Print Post   Remind Me!   Notify Moderator  
ncskywarn
Registered User


Reged: Mon
Posts: 5
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: hurricane expert]
      #86688 - Tue Sep 01 2009 04:54 AM

Looking at the latest satellite image it still looks like its under some shear .

--------------------
Certified Skywarn Spotter


Post Extras: Print Post   Remind Me!   Notify Moderator  
berrywr
Weather Analyst


Reged: Fri
Posts: 370
Loc: Opelika, AL 32.71N 85.23W
Re: Wave East of Caribbean Likely to Develop Today or Tomorrow [Re: ncskywarn]
      #86689 - Tue Sep 01 2009 06:42 AM

01/10Z - Good morning! At first glance you'd think 94L is a Tropical Depression, possibly a Tropical Storm. Once again, the upper environment directly over 94L and to its right is downright perfect for development; the problems arise with the upper low to the north of Hispanola and strong SW shear immediately to it's east and immediately to 94L's west and north. We're all looking at satellite and telling ourselve it looks like its ready to be promoted to tropical storm status. I don't have at my disposal what the shear forecast is along the path of the storm nor the array of charts and model data NHC has. A snapshot of the upper environment currently on its projected course is downright hostile for the time being and closer examination of the satellite interpretation reveals this to be true if you look at the higher cloud tops to the west and north of what we believe is the center of the system.

Looking at the overall pattern this morning, not much has changed since this time yesterday. Looking at new model data and what we all know is true about dying fronts in the GOM and Atlantic is it looks like they're trying to cook something up off the Atlantic Coast, but before I buy into that we all have to keep in mind what the overall pattern is right now and that is there is a longwave trough over the eastern half of the US and it is broad. Borrowing a page from Danny, any shortwave energy dropping into the base of the trough and ejecting northeast is likely to promote cyclogenesis along the old front; in this case, not likely to be tropical, but extratropical. As long as the longwave is there GOM is closed to tropical formation and in fact shear analysis only supports an area near the FL keys that has an environment friendly for development. Anything does develop it will be a dynamic system; not tropical.

All that said, it's possible 94L could be designated either a strong tropical depression or weak storm. There is no way at this time the system can develop in front of the shear that is in front of it unless the light environment that is over and immediately to its east rides with the storm. The upper low is expected to remain in the area at least through H+48 hours and upper ridge to the north of the system. After that, upper models get interesting and I wouldn't be surprised based on what I'm looking at that the systems meanders around north of Puerto Rico and if that happens then all bets are off as the longwave trough over the east weakens and the upper ridge in the Atlantic begins to make its presence known. In fairness, the models don't have a good handle on 94L and barely even pick it up at the upper levels, but it is there in the low levels.

Bottom line 94L for the near future has a tough road to hoe with shear ahead of the system; as we move forward and upper pattern changes, stay tune. I don't think whatever cyclogenesis occurs off the Atlantic coast will have anything to do with 94L which too far away at this time; unlike Danny, who got absorbed as the upper low ejecting out of the SE USA a few days ago. I'm not as confident long term as I was yesterday and day before with this system staying away from the United States.

Finally, our thoughts and prayers are with our Baja California neighbors.

--------------------
Sincerely,

Bill Berry

"To work in the service of life and the living..." - John Denver

Edited by AlaberryPatch (Tue Sep 01 2009 07:03 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
94L [Re: berrywr]
      #86690 - Tue Sep 01 2009 07:23 AM

Awesome update.
Here's San Juan NWS morning AFD excerpt.

FCST FOR THU-FRI WILL BE HIGHLY DEPENDENT ON THE TRACK/EVOLUTION
OF BROAD AREA OF LOW PRES LOCATED ABOUT 350 MILES EAST OF THE
LEEWARD ISLANDS WHICH AT THIS TIME REMAINS HIGHLY UNCERTAIN.
CENTER FIXES DONE AT 06Z BY TAFB AND SAB AGENCIES WERE
AT 16.3N 55.6W AND 16.4N 55.9W RESPECTIVELY. COORDINATED WITH
BOTH ANALYSTS ON THE PHONE THIS MORNING AND BOTH INDICATED A LOW
CONFIDENCE IN THEIR RESPECTIVE FIXES WITH THE POSSIBILITY OF
MULTIPLE CENTERS. A 0406Z TMI MICROWAVE PASS SUGGESTS THE LOW
LEVEL CENTER IS ON THE WESTERN EDGE OF THE CONVECTION BUT WITH NO
CLOSED CIRCULATION YET. 06Z EARLY CYCLE NHC MODELS SHOW TRACKS
RANGING FROM ALONG THE SOUTH COAST OF PR TO AS FAR NORTH AS 20N
IN THE 72 TO 96 HR TIME FRAME OR THU NIGHT THROUGH FRI NIGHT BUT
DO NOT EXPECT MODELS TO GET A GOOD HANDLE ON THE TRACK FCST UNTIL
AT LEAST ANOTHER 24 TO 36 HRS. INTERESTS IN PR/USVI ARE REMINDED
THAT TRACK FORECAST ERRORS CAN BE IN THE ORDER OF 167 TO 230
NAUTICAL MILES IN THE 72 TO 96 HR TIME FRAME. THE FIRST HURRICANE
HUNTER PLANE IS SCHEDULED TO INTERCEPT THE DISTURBANCE THIS
AFTERNOON AT 2PM AND WILL GIVE A BETTER PICTURE OF THE STRUCTURE
OF THE STORM...ITS EXACT LOCATION AND WIND FIELD.
There is a lot more to the San Juan AFD. Follow the link below.. danielw
http://www.srh.noaa.gov/printable.php?pil=AFD&sid=SJU&date=2009-09-01%2008:22:24

Edited by danielw (Tue Sep 01 2009 07:28 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
OrlandoDan
Storm Tracker


Reged: Mon
Posts: 267
Loc: Longwood, FL 28.69N 81.44W
Re: 94L [Re: danielw]
      #86691 - Tue Sep 01 2009 07:28 AM

...and just to add the remainder from Daniel's post from PR....

AS MENTIONED IN THE TROPICAL DISCUSSION FROM HPC`S INTERNATIONAL
DESK YESTERDAY...THE FLOW DOMINATING THE ATLC TO THE NORTH OF 20N
AND TO THE EAST OF 70W IS CHARACTERIZED BY NUMEROUS TUTT LOWS WITH
CELLS OF THE SUBTROPICAL RIDGE BEING MIGRATORY AND OF SHORT
DURATION RESULTING IN VERY ILL DEFINED STEERING CURRENTS. I WOULD
EXPECT THE TRACK FCST WITH THIS STORM TO BE EXTREMELY CHALLENGING
WITH LOTS OF ERRATIC MOVEMENTS AND WOBBLES WITH A MUCH HIGHER THAN
AVERAGE UNCERTAINTY.

THE BIGGEST THREAT FROM THE STORM IS THE POTENTIAL TO PRODUCE A
TON OF RAINFALL ALONG AND NEAR THE TRACK OF THE STORM WHICH IS
STILL HIGHLY UNCERTAIN AS MODELS SUGGEST SYSTEM MOVING AT AVERAGE
OF SPEED OF ABOUT 7 KTS AS IT MOVES ACROSS THE REGIONAL WATERS
WITH THE GFDL INDICATING SPEEDS AS SLOW AS 4 KT AT TIMES. THE MOST
LIKELY TIME FRAME FOR POTENTIAL IMPACTS LOOKS TO BE BETWEEN THU
NIGHT AND FRI NIGHT. SINCE THIS IS STILL BEYOND 48 HRS IT IS TOO
EARLY TO ISSUE ANY FLASH FLOOD WATCHES AT THIS TIME.

HURRICANE STATEMENT WILL BE FRESHEN LATER THIS MORNING TO UPDATE
STORM POSITION AND POTENTIAL IMPACTS.

--------------------
Keith (1988), Charley (2004), Frances (2004) , Jeanne (2004), Fay (2008)


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
Re: 94L and GOM? [Re: OrlandoDan]
      #86692 - Tue Sep 01 2009 08:20 AM

A few of the NWS Offices along the Gulf Coast are mentioning a tropical/ hybrid type system spin up this week in the GOM.
While looking through the extended forecast matrices from New Orleans and eastward I noticed that all of the Coastal stations are forecast to have increasing easterly wind beginning Sunday. In the 8 to 14 mph range.
Not indicative in itself but again something to watch... out the back door.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hawkeyewx
Weather Analyst


Reged: Sun
Posts: 63
Re: 94L [Re: OrlandoDan]
      #86693 - Tue Sep 01 2009 08:27 AM

One of the first rules of following tropical cyclone formation is... focus on the surface flow, not the pretty blobs. Tropical cyclones are surface based systems. You can have the most intense-looking, vigorously spinning blob you've ever seen, but if there is no surface organization there is no tropical cyclone... just an impressive MCS. 94L's organization continues to be poor.

Post Extras: Print Post   Remind Me!   Notify Moderator  
LoisCane
Veteran Storm Chaser


Reged: Fri
Posts: 1212
Loc: South Florida
Re: 94L [Re: Hawkeyewx]
      #86694 - Tue Sep 01 2009 09:26 AM

okay well, why is it not organized at the surface, i had just joked to someone it is that ...but don't mesoscales move a little faster, can't see this really being just the world's slowest, largest moving mescoscale. Something is missing because I just don't buy that it can stay together so well and ventilate without some low level circulation. '

Is there a mid level? Are there no ship reports or anything from this area for surface obs?

--------------------
http://hurricaneharbor.blogspot.com/


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hawkeyewx
Weather Analyst


Reged: Sun
Posts: 63
Re: 94L [Re: LoisCane]
      #86695 - Tue Sep 01 2009 09:36 AM

Quote:

okay well, why is it not organized at the surface, i had just joked to someone it is that ...but don't mesoscales move a little faster, can't see this really being just the world's slowest, largest moving mescoscale. Something is missing because I just don't buy that it can stay together so well and ventilate without some low level circulation. '

Is there a mid level? Are there no ship reports or anything from this area for surface obs?




Organization is not good, mainly due to southwesterly shear and elongation that can be tough to get rid of, but it is still a significant wave with good convergence east of the center. The eastern half is also further under an upper ridge so the blob has decent ventilation. The persistent intense blob has also created its own mid-level vorticity and that helps to keep the convection going.

Bottom line... the southwesterly shear over the west half of this system must ease if it is to develop.


Post Extras: Print Post   Remind Me!   Notify Moderator  
craigm
Storm Tracker


Reged: Wed
Posts: 245
Loc: Palm City, Florida 27.17N 80.27W
Re: 94L [Re: Hawkeyewx]
      #86696 - Tue Sep 01 2009 10:33 AM

Wow , talk about a puzzle. This is the first time I have seen a storm develop at the upper levels first. Broad undefined circulation feeding the outflow. When this finally closes off at the surface there is no predicting the intensity. The leewards better be watching this as I am sure they are. If it looks like, walks like and quacks like a duck I guess its not a duck.

--------------------
Why I'm here:
Frances,Jeanne,Wilma,worked on Andrew damage


Post Extras: Print Post   Remind Me!   Notify Moderator  
LoisCane
Veteran Storm Chaser


Reged: Fri
Posts: 1212
Loc: South Florida
Re: 94L [Re: Hawkeyewx]
      #86697 - Tue Sep 01 2009 10:43 AM

"persistent intense blob has also created its own mid-level vorticity and that helps to keep the convection going."

Thanks... will go with that for now. Makes sense.

I tell myself this is not normal, then I remember Debby, and remember that seemed not normal too!!



--------------------
http://hurricaneharbor.blogspot.com/


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hugh
Senior Storm Chaser


Reged: Fri
Posts: 1060
Loc: Okaloosa County, Florida 30.51N 86.50W
Re: 94L [Re: craigm]
      #86698 - Tue Sep 01 2009 11:00 AM

Quote:

Wow , talk about a puzzle. This is the first time I have seen a storm develop at the upper levels first. Broad undefined circulation feeding the outflow. When this finally closes off at the surface there is no predicting the intensity. The leewards better be watching this as I am sure they are. If it looks like, walks like and quacks like a duck I guess its not a duck.




I have not heard any recent reports today but at one point I believe the system had gail-force winds, meaning the only thing it lacked to keep it from being Erika was a closed low. I assume that is still the case given current satelllite appearance (black on the AVN loop until about an hour ago). I jokingly said to someone last night, that 94L, not even organized enough to be a depression, had deeper convection than Jimena did at its peak intensity. Obviously 94L is not a Cat-5 hurricane, but if it were not for the shear, it could develop rapidly.

Currently, it looks less organized to me than it did a few hours ago, so I think they will wait for recon reports before pulling the trigger, and it would surprise me for recon to find a closed LLC.

--------------------
Hugh

Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)


Post Extras: Print Post   Remind Me!   Notify Moderator  
JMII
Weather Guru


Reged: Thu
Posts: 161
Loc: Margate, Florida 26.26N 80.22W
Re: 94L [Re: craigm]
      #86699 - Tue Sep 01 2009 11:04 AM

Quote:

Wow , talk about a puzzle. This is the first time I have seen a storm develop at the upper levels first. Broad undefined circulation feeding the outflow. When this finally closes off at the surface there is no predicting the intensity.




Agreed. I've seen the NHC call much more disorganized blobs of nothing a TS and often questioned their reasoning behind it. Then you get a storm like this which looks like a very healthy TS, but the NHC still has it only labeled as an Invest. The outflow is incredible on this system, if it can over come the shear & get a low-level center it could quickly ramp up. The computer models can't get a handle on it either, some are saying it could drift west for days and still not develop much.

The visual satellite loop shows a slight low-level circulation to the west but the shear is pushing all the thunderstorms off to the east. The water vapor loop shows what looks like your typical tropical system with a deep center core and lighter outflow moving around it. Yet at this time we got nothing... very strange indeed.

--------------------
South FL Native... experienced:
David ('79) - Floyd ('87) - Andrew ('92) - Georges ('98) - Irene ('99) - Frances & Jeanne ('04) - Katrina & Wilma ('05)


Post Extras: Print Post   Remind Me!   Notify Moderator  
MikeCAdministrator
Admin


Reged: Sun
Posts: 2956
Loc: Orlando, FL 28.49N 81.47W
Re: 94L [Re: JMII]
      #86700 - Tue Sep 01 2009 11:09 AM

This is one of the oddest systems I've seen to date too. If anything does form at the surface it could ramp up quite quickly. Apparent center still seems elongated, at this point really I think they are just waiting for recon. This system would make a good case study for storm development.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Evan Johnson
Weather Guru


Reged: Fri
Posts: 143
Loc: Loxahatchee, FL 26.79N 80.28W
Re: 94L [Re: MikeC]
      #86701 - Tue Sep 01 2009 11:29 AM

it is a very interesting storm to say in the least. i still cant believe the NHC waiting till the thing is 200 miles away from the leeward islands and they still havent dubbed it a storm. talk about last minute. you are right though mike. as soon as that plane comes back they will dub it a storm due to the fact everything else they see confuses them as much as it confuses us. afterall someone once said "you want to know if its cloudy? go outside.". i would venture to say however, it wont take anymore then the rest of this afternoon to dub it a storm.

Post Extras: Print Post   Remind Me!   Notify Moderator  
MichaelA
Weather Analyst


Reged: Thu
Posts: 817
Loc: Pinellas Park, FL 27.83N 82.69W
Re: 94L [Re: Evan Johnson]
      #86702 - Tue Sep 01 2009 11:40 AM

It looks a lot like Danny did. Tilted system with good mid and upper level structure, but weak low level presence.

--------------------
Michael
2014: 8/2/0
2014 Actual: 5/4/1


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
Re: 94L [Re: Evan Johnson]
      #86703 - Tue Sep 01 2009 11:47 AM

Easy now...
I too believe that it's probably a Depression at the least. At the surface.
Visible shots of the mid and upper levels reveal something akin to a Tropical Storm with really nice outflow overhead. Which is normally conducive for development.


Post Extras: Print Post   Remind Me!   Notify Moderator  
berrywr
Weather Analyst


Reged: Fri
Posts: 370
Loc: Opelika, AL 32.71N 85.23W
Re: 94L [Re: MikeC]
      #86704 - Tue Sep 01 2009 12:02 PM

If a tropical system looks like a depression or storm is it odd? Like Danny, the upper environment around 94L is just plain hostile and closer examination of satellite images reveals the fact that whatever vertical depth 94L/Erika obtains, is likely to be sheared apart if the light shear directly over the system; and I mean dead over it doesn't move with the system with the exception of confluence at the low levels and difluence aloft; it may look pretty, but it has no chance of structurally developing as long as that pesty upper low north of Hispanola exists and remains nearby.

If 94L remains shallow enough as the upper environment becomes less hostile then and only then will we be talking about where it will go. There are some hints in the model data that 94L/Erika will be with us for a while, especially if the upper (Bermuda-Azore) ridge begins to strengthen and make its presence known to its west and the persistent longwave trough over the eastern US weakens and retreats north.

In the here and now, it would be torn apart with the shear that is currently in place along its course.

--------------------
Sincerely,

Bill Berry

"To work in the service of life and the living..." - John Denver


Post Extras: Print Post   Remind Me!   Notify Moderator  
berrywr
Weather Analyst


Reged: Fri
Posts: 370
Loc: Opelika, AL 32.71N 85.23W
Re: 94L [Re: danielw]
      #86705 - Tue Sep 01 2009 12:14 PM

That is not outflow. This is shear. Please take a closer look at both the current Wind Shear analysis out of SSEC and satellite imagery of the adjacent cells around 94L. Wind Shear analysis will confirm there are 30 to 50 knots southwest winds aloft along its course and 20 knots of north winds aloft to its east and southeast. There is very light shear directly over the system and to its northeast where analysis indicates 10 knots. Outflow or the mechanism which a tropical storm/hurricane has cirrus rotating anti-cyclonic away from it requires an upper ridge/high above the system...think of it as breathing...air rises up the center of the system and is directed away at the top. Shear in the configuration it is currently can be interpreted as outflow because of the directions in this case were talking about. Whether the system is classified a depression or storm is not as important as for the immediate future what lies aloft in its way. Today, the system is in a tough, tough environment aloft! A couple of days from now or a slow moving system where the light shear over it remains in place as it travels west northwest is the only way this system can survive in the near term. The models are hinting at changes which are more conducive for 94L to develop into something more substantial, but not today.

--------------------
Sincerely,

Bill Berry

"To work in the service of life and the living..." - John Denver


Post Extras: Print Post   Remind Me!   Notify Moderator  
berrywr
Weather Analyst


Reged: Fri
Posts: 370
Loc: Opelika, AL 32.71N 85.23W
NWSFO - San Juan - Area Forecast Discussion [Re: MikeC]
      #86706 - Tue Sep 01 2009 12:25 PM

000
FXCA62 TJSJ 011435
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
1035 AM AST TUE SEP 1 2009

.SYNOPSIS...MID-UPPER LEVEL RIDGING WILL BUILD INTO THE REGION
TODAY AND MAINTAIN A SUBSIDENT PATTERN ACROSS THE REGION THROUGH
TOMORROW. BROAD AREA LOW PRES TO THE EAST OF THE LEEWARD ISLANDS
STILL NOT WELL ORGANIZED BUT COULD BECOME THE FIFTH NAMED STORM OF
THE 2009 HURRICANE SEASON AND MAY IMPACT THE ISLANDS OF THE NORTHEAST
CARIBBEAN TOWARD THE END OF THE WORK WEEK. INTERESTS IN PR/USVI
SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.

DISCUSSION...FCST FOR TODAY IS QUITE SIMPLE. LARGE SCALE
SUBSIDENCE WILL ENCOMPASS THE REGION TODAY THROUGH TOMORROW AS
HEIGHTS RISE IN RESPONSE TO BUILDING MID-UPPER LVL RIDGE. THIS
WILL SIGNIFICANTLY LIMIT SHOWER ACTIVITY OVR THE NEXT 48 HRS. SHOWERS
IF ANY WILL BE CONFINED TO THE SOUTHWEST CORNER OF PR DUE TO
NORTHEAST WINDS.

FCST FOR THU-FRI WILL BE HIGHLY DEPENDENT ON THE TRACK/EVOLUTION
OF BROAD AREA OF LOW PRES LOCATED ABOUT 350 MILES EAST OF THE
LEEWARD ISLANDS WHICH AT THIS TIME REMAINS HIGHLY UNCERTAIN.
CENTER FIXES DONE AT 06Z BY TAFB AND SAB AGENCIES WERE
AT 16.3N 55.6W AND 16.4N 55.9W RESPECTIVELY. COORDINATED WITH
BOTH ANALYSTS ON THE PHONE THIS MORNING AND BOTH INDICATED A LOW
CONFIDENCE IN THEIR RESPECTIVE FIXES WITH THE POSSIBILITY OF
MULTIPLE CENTERS. A 0406Z TMI MICROWAVE PASS SUGGESTS THE LOW
LEVEL CENTER IS ON THE WESTERN EDGE OF THE CONVECTION BUT WITH NO
CLOSED CIRCULATION YET. 06Z EARLY CYCLE NHC MODELS SHOW TRACKS
RANGING FROM ALONG THE SOUTH COAST OF PR TO AS FAR NORTH AS 20N
IN THE 72 TO 96 HR TIME FRAME OR THU NIGHT THROUGH FRI NIGHT BUT
DO NOT EXPECT MODELS TO GET A GOOD HANDLE ON THE TRACK FCST UNTIL
AT LEAST ANOTHER 24 TO 36 HRS. INTERESTS IN PR/USVI ARE REMINDED
THAT TRACK FORECAST ERRORS CAN BE IN THE ORDER OF 167 TO 230
NAUTICAL MILES IN THE 72 TO 96 HR TIME FRAME. THE FIRST HURRICANE
HUNTER PLANE IS SCHEDULED TO INTERCEPT THE DISTURBANCE THIS
AFTERNOON AT 2PM AND WILL GIVE A BETTER PICTURE OF THE STRUCTURE
OF THE STORM...ITS EXACT LOCATION AND WIND FIELD.

AS MENTIONED IN THE TROPICAL DISCUSSION FROM HPC`S INTERNATIONAL
DESK YESTERDAY...THE FLOW DOMINATING THE ATLC TO THE NORTH OF 20N
AND TO THE EAST OF 70W IS CHARACTERIZED BY NUMEROUS TUTT LOWS WITH
CELLS OF THE SUBTROPICAL RIDGE BEING MIGRATORY AND OF SHORT
DURATION RESULTING IN VERY ILL DEFINED STEERING CURRENTS. I WOULD
EXPECT THE TRACK FCST WITH THIS STORM TO BE EXTREMELY CHALLENGING
WITH LOTS OF ERRATIC MOVEMENTS AND WOBBLES WITH A MUCH HIGHER THAN
AVERAGE UNCERTAINTY.

THE BIGGEST THREAT FROM THE STORM IS THE POTENTIAL TO PRODUCE A
TON OF RAINFALL ALONG AND NEAR THE TRACK OF THE STORM WHICH IS
STILL HIGHLY UNCERTAIN AS MODELS SUGGEST SYSTEM MOVING AT AVERAGE
OF SPEED OF ABOUT 7 KTS AS IT MOVES ACROSS THE REGIONAL WATERS
WITH THE GFDL INDICATING SPEEDS AS SLOW AS 4 KT AT TIMES. THE MOST
LIKELY TIME FRAME FOR POTENTIAL IMPACTS LOOKS TO BE BETWEEN THU
NIGHT AND FRI NIGHT. SINCE THIS IS STILL BEYOND 48 HRS IT IS TOO
EARLY TO ISSUE ANY FLASH FLOOD WATCHES AT THIS TIME.
http://forecast.weather.gov/product.php?...&glossary=1

--------------------
Sincerely,

Bill Berry

"To work in the service of life and the living..." - John Denver

Edited by danielw (Tue Sep 01 2009 01:37 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
berrywr
Weather Analyst


Reged: Fri
Posts: 370
Loc: Opelika, AL 32.71N 85.23W
HPC - Carribbean Forecast Discussion [Re: berrywr]
      #86707 - Tue Sep 01 2009 12:26 PM

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
237 PM EDT MON AUG 31 2009

THE PERTURBATION ALONG 52W BECAME VERY ACTIVE DURING THE EARLY
MORNING HOURS...TAKING ADVANTAGE OF CONVECTIVE INSTABILITY TO
SUSTAIN A FLARE UP IN CONVECTIVE ACTIVITY. BUT MODERATE SHEAR
COMBINED WITH INFLOW OF DRY AIR DAMPENED FURTHER
INTENSIFICATION...WITH IR IMAGES NOW SHOWING WARMING TOPS. THE
INFLOW OF DRY AIR IS EVIDENT ON THE BLENDED TPW PRODUCT...AND BOTH
THE GFS/ECMWF SEEM TO HAVE CAPTURE THIS QUITE WELL. AS THE
PERTURBATION ENTERS THE CARIBBEAN THE MODELS AGREE ON SOME OF THE
ENERGY SHEARING NORTH OF THE ISLANDS WHILE THE REST CONTINUES TO
THE WEST ACROSS THE BASIN. THEY THEN FORECAST THE NORTHERN SEGMENT
TO EVOLVE INTO AN ILL ORGANIZED LOW BY MID CYCLE. THE SOUTHERN
SEGMENT WILL CONTINUE INTO THE CARIBBEAN AS INDICATED ABOVE. OVER
THE ISLAND CHAIN WE EXPECT ACCUMULATION OF 00-05MM/DAY AND MAXIMA
OF 10-15MM/DAY ON DAY 02...WHILE OVER THE VIRGIN ISLANDS/PUERTO
RICO IT WILL FAVOR ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF
25-50MM/DAY. OVER NORTHERN GUYANA/ORINOCO DELTA REGION WE EXPECT
ACCUMULATION OF 10-15MM/DAY AND MAXIMA OF 25-40MM/DAY.
http://www.hpc.ncep.noaa.gov/discussions/fxca20.html


--------------------
Sincerely,

Bill Berry

"To work in the service of life and the living..." - John Denver

Edited by danielw (Tue Sep 01 2009 01:31 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
scottsvb
Weather Master


Reged: Mon
Posts: 1096
Loc: fl
Re: HPC - Carribbean Forecast Discussion [Re: berrywr]
      #86708 - Tue Sep 01 2009 01:03 PM

94L does have a closed LLC now...albeit weak of 1009mbs heading WNW or 290dg... its circulation is small..and lacking T-Storms near the center.....still though T-Storms with winds around 40-50mph are placed well east of the center by over 100 miles due to the shear over the LLC. The NHC can classify this as a TD since it does now have a LLC and slight chance a T.S. but I doubt they will go that high due to the lacking of T-Storms over the LLC.
Models will still diverge some until the system gets better organized...if it does @ all. Shear is the main factor... a more developed system will move more NW...a sheared system will move more W or WNW over the next few days.


Post Extras: Print Post   Remind Me!   Notify Moderator  
weathernet
Storm Tracker


Reged: Sat
Posts: 296
Loc: Elsewhere 80.30N 50.63E
Re: 94L [Re: danielw]
      #86709 - Tue Sep 01 2009 01:16 PM

Very interesting system. Appears to me what was perhaps a looser tilted broad center, might now be slowly coming closer to closing off. At this point any improvement from yesterday's low level structure is still perhaps moot. Which is not to say that NHC won't classify this as a depression, following today's recon intercept. My guess is that assuming that recon measures winds to gale force, if even well removed from the center, that they will in fact find light west winds at the surface, and a broad ( but slightly improved & "co-located" ) surface low on the systems west side ), thus technically closing off a low. Point being, this system continues to move in a fashion perhaps close enough to the Northern Leewards and Puerto Rico and though slightly subtle changes could rip 94L apart, equally subtle changes could allow some significant development. Even given upper air conditions remaining unchanged for 24-36 hours, SST's should be slightly on the increase to a mean temp of 29C ( or perhaps slightly higher ).

Will the upper low continue further impinge on 94L or perhaps at minimum, move generally westward in tandem with it? Outflow in the eastern quadrant, as observed by others remains healthy. Given the girth of 94L, and if it were to slow down as some models anticipate, than given the vigorous mid level structure it seems to have developed, I would tend to think that the upper level ridge hanging onto the systems east side, might build more firmly over this system. If such were to occur, and assuming the systems present size and mid level structure, than like others, I would agree could undergo some impressive and fast deepening. It is slightly interesting that though the model trends for intensity have not changed much, the GFDL has jumped on the bandwagon for development, rather than carrying this as an open wave.

Given any mid term long wave pattern shift, this would no doubt impact the motion and transiency of not just 94L, but of other inhibiting mid/upper level forces currently at play.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hugh
Senior Storm Chaser


Reged: Fri
Posts: 1060
Loc: Okaloosa County, Florida 30.51N 86.50W
Re: HPC - Carribbean Forecast Discussion [Re: scottsvb]
      #86710 - Tue Sep 01 2009 01:17 PM

if it looks like a duck, walks like a duck, and quacks when you squeeze it.... it might just be pretending to be a duck.
Given the appearance of a LLC now, albeit one way ahead of the convection, I don't see how the NHC can hold the trigger and NOT call it at least a depression. The question is, will the LLC survive? If it were even on the outer fringe of the CDO, I'd give it a decent chance. Where it is.... it's not going to do much except bring a lot of rains to the northern islands.

--------------------
Hugh

Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hawkeyewx
Weather Analyst


Reged: Sun
Posts: 63
Re: HPC - Carribbean Forecast Discussion [Re: scottsvb]
      #86711 - Tue Sep 01 2009 01:21 PM

There is certainly a main surface vortex easily seen on the visible loop. It's not real strong, but the recon plane currently approaching the system may be able to close it off. If they do, it wouldn't surprise me if the NHC named it. The shear still needs to drop, though, for this system to do anything major.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Beach
Weather Guru


Reged: Wed
Posts: 187
Loc: Cocoa Beach/Banana River
Re: HPC - Carribbean Forecast Discussion [Re: Hawkeyewx]
      #86712 - Tue Sep 01 2009 01:28 PM

There is a westerly wind at the surface:
Wind Direction (WDIR): SSW ( 200 deg true )
Wind Speed (WSPD): 21.0 kts
Wave Height (WVHT): 5.6 ft
Dominant Wave Period (DPD): 7 sec
Atmospheric Pressure (PRES): 29.87 in
Pressure Tendency (PTDY): -0.03 in ( Falling )
Air Temperature (ATMP): 82.9 °F
Water Temperature (WTMP): 82.4 °F
Dew Point (DEWP): 76.5 °F
Heat Index (HEAT): 91.4 °F

http://www.ndbc.noaa.gov/station_page.php?station=41101


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
94L [Re: Hawkeyewx]
      #86713 - Tue Sep 01 2009 01:42 PM

So far the winds being reported by RECON don't quite meet the Tropical Storm speeds.
I believe the highest so far was 40 mph at flight level. Even though they are close, they Still have to close off a Low before 94L advances to the next level or Tropical Depression status.


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
Posts [Re: danielw]
      #86714 - Tue Sep 01 2009 01:48 PM

Please don't post the WHOLE bulletin or statement from Official sources when posting.
Edit the post down to a few paragraphs and post a link to the Bulletin you are quoting from.
It will save time on everyone's part.
Thanks


Post Extras: Print Post   Remind Me!   Notify Moderator  
weathernet
Storm Tracker


Reged: Sat
Posts: 296
Loc: Elsewhere 80.30N 50.63E
Re: HPC - Carribbean Forecast Discussion [Re: Beach]
      #86715 - Tue Sep 01 2009 01:53 PM

Taking a quick look at the GFS 12Z 200mb forecast, it would seem plainly clear that the shear that 94L is undergoing, is to certainly lessen with time. In fact, upper level southerly flow seems to back off somewhat and as soon as 18 hours from when initialed. Energy from the upper low well north of Hispaniola is progged to basically be pulled northward and absorbed well north and into the retreating westerlies. Significant upper air pattern changes seem to occur, especially starting in the 56 hour range. Upper high "bubble" currently slightly over and eastward of 94L seems to move westward with time, and a more overall area of bridged ridging seems to ensue.

Have not seen any 12Z Euro upper air data from today, but given the relative near term GFS upper air forecast, along with the European's recent trends to show rising heights over the Western Atlantic and Eastern CONUS, lead me to believe that unless 94L gets shredded during the next 24 hours, eventual intensification would be a given. Though I would not expect significant improvement in 94L's overall structure, I would be somewhat surprised in its near term to see its total demise. Providing this system is capable of fairly consistent bursting of convection, than aside from whether or not recon will cause NHC to classify this as a depression ( I think it will ), more important will be "what" it might be in 72 hours.

2:00pm T.W.O. from NHC just in......

ABNT20 KNHC 011751
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT TUE SEP 1 2009

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

SATELLITE IMAGES INDICATE THAT A LOW PRESSURE AREA LOCATED ABOUT 260
MILES EAST OF THE LEEWARD ISLANDS COULD BE DEVELOPING A WELL-DEFINED
SURFACE CENTER. AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT IS
CURRENTLY INVESTIGATING THE SYSTEM TO SEE IF A TROPICAL CYCLONE HAS
FORMED. THIS SYSTEM COULD BECOME A TROPICAL DEPRESSION OR...MORE
LIKELY...A TROPICAL STORM AT ANY TIME OVER THE NEXT COUPLE OF DAYS
AS IT MOVES WEST-NORTHWESTWARD AT AROUND 10 MPH............

Edited by weathernet (Tue Sep 01 2009 01:58 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
weathernet
Storm Tracker


Reged: Sat
Posts: 296
Loc: Elsewhere 80.30N 50.63E
Re: HPC - Carribbean Forecast Discussion [Re: weathernet]
      #86716 - Tue Sep 01 2009 02:25 PM

Qucik note, upon closer observation of current 1KM vis. satellite, it appears that a fairly well and tight LLC has in fact formed around 17N and 57W. Looks like convective tops are starting to "pop" right on the eastern side of this feature. Overall apparent LLC looks to be not moving, yet convective mid level continues to slide WNW and is becoming closer to this feature. Banding feature also now starting to pull moisture up and into the south side of this apparent LLC. I would perhaps expect a short term hop more WNW or NW over this evening hours should a somewhat better co-alignment be taking place.

Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
Re: HPC - Carribbean Forecast Discussion [Re: weathernet]
      #86717 - Tue Sep 01 2009 02:25 PM

RECON data looks real close. I've seen NE and SSW windirections and SFMR surface wind speeds close to Tropical Storm force. But we'll have to wait and see if NHC pulls the CODE Green...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Hugh
Senior Storm Chaser


Reged: Fri
Posts: 1060
Loc: Okaloosa County, Florida 30.51N 86.50W
Re: HPC - Carribbean Forecast Discussion [Re: danielw]
      #86718 - Tue Sep 01 2009 02:28 PM

Quote:

RECON data looks real close. I've seen NE and SSW windirections and SFMR surface wind speeds close to Tropical Storm force. But we'll have to wait and see if NHC pulls the CODE Green...




Uh, I know I'm sick and my mind is not working right but *what* is CODE Green?

It looks like convection MAY be trying to wrap around the developing LLC. It's going to be very interesting to see if they call it a TD or a storm.

--------------------
Hugh

Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
Re: HPC - Carribbean Forecast Discussion [Re: Hugh]
      #86719 - Tue Sep 01 2009 02:34 PM

Code Green is the next level.... A numbered or named system. Hypothetical/ Pessimistic/ Optimistic color that I came up with.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Hugh
Senior Storm Chaser


Reged: Fri
Posts: 1060
Loc: Okaloosa County, Florida 30.51N 86.50W
Re: HPC - Carribbean Forecast Discussion [Re: danielw]
      #86720 - Tue Sep 01 2009 02:43 PM

I think of Code Green as "all clear" LOL

--------------------
Hugh

Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
Re: HPC - Carribbean Forecast Discussion [Re: Hugh]
      #86721 - Tue Sep 01 2009 02:47 PM

That would depend on whether you are ahead or behind the storm I guess.
I don't know what other colors would be above yellow, orange and red... infrared?
Code Blue or Black. But I think we've hashed it enough.

I just noticed the wording in the 2 PM Trop. Outlook from NHC.

AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT IS
CURRENTLY INVESTIGATING THE SYSTEM TO SEE IF A TROPICAL CYCLONE HAS
FORMED.
THIS SYSTEM COULD BECOME A TROPICAL DEPRESSION OR... MORE LIKELY... A TROPICAL STORM AT ANY TIME OVER THE NEXT COUPLE OF DAYS AS IT MOVES WEST-NORTHWESTWARD AT AROUND 10 MPH.

Edited by danielw (Tue Sep 01 2009 02:50 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hawkeyewx
Weather Analyst


Reged: Sun
Posts: 63
Re: HPC - Carribbean Forecast Discussion [Re: weathernet]
      #86722 - Tue Sep 01 2009 02:51 PM

Quote:

Qucik note, upon closer observation of current 1KM vis. satellite, it appears that a fairly well and tight LLC has in fact formed around 17N and 57W. Looks like convective tops are starting to "pop" right on the eastern side of this feature. Overall apparent LLC looks to be not moving, yet convective mid level continues to slide WNW and is becoming closer to this feature. Banding feature also now starting to pull moisture up and into the south side of this apparent LLC. I would perhaps expect a short term hop more WNW or NW over this evening hours should a somewhat better co-alignment be taking place.




I concur. The surface vortex was moving steadily wnw/nw all morning, but the convection has given it a little tug, leading to a north wobble. Any temporary halting of the vort's west movement can only improve the system's chance of development as it gives the shear zone time to back off a bit.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hugh
Senior Storm Chaser


Reged: Fri
Posts: 1060
Loc: Okaloosa County, Florida 30.51N 86.50W
Re: HPC - Carribbean Forecast Discussion [Re: danielw]
      #86723 - Tue Sep 01 2009 02:56 PM

Quote:

That would depend on whether you are ahead or behind the storm I guess.
I don't know what other colors would be above yellow, orange and red... infrared?
Code Blue or Black. But I think we've hashed it enough.

I just noticed the wording in the 2 PM Trop. Outlook from NHC.

AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT IS
CURRENTLY INVESTIGATING THE SYSTEM TO SEE IF A TROPICAL CYCLONE HAS
FORMED.
THIS SYSTEM COULD BECOME A TROPICAL DEPRESSION OR... MORE LIKELY... A TROPICAL STORM AT ANY TIME OVER THE NEXT COUPLE OF DAYS AS IT MOVES WEST-NORTHWESTWARD AT AROUND 10 MPH.




Yep, basically they are waiting for recon confirmation is the way I read it. Before putting up a tropical storm warning for Erika, they want to confirm the existence of Erika.

--------------------
Hugh

Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)


Post Extras: Print Post   Remind Me!   Notify Moderator  
danielwAdministrator
Moderator


Reged: Wed
Posts: 3460
Loc: Hattiesburg,MS (31.3N 89.3W)
Recon [Re: Hugh]
      #86724 - Tue Sep 01 2009 03:29 PM

Bet's are off it's still 50-50 on whether 94L attains TD5 or Tropical Storm Erika status.
As of 1907Z lowest filght level pressure 1007.0mb or (~29.74 inHg) maximum flight level wind speed so far is 49kts (~56.3mph) and the maximum SFMR estimated surface windspeed is 42kts (~48.3mph).


Post Extras: Print Post   Remind Me!   Notify Moderator  
Storm Hunter
Veteran Storm Chaser


Reged: Wed
Posts: 1370
Loc: Panama City Beach, Fl. 30.16N 85.76W
Re: HPC - Carribbean Forecast Discussion [Re: Hugh]
      #86725 - Tue Sep 01 2009 03:31 PM Attachment (188 downloads)

Current recon has been flying on the west side of convection... they looked to have hit a area that could of been a the old level center... on the WSW side of convection... current flight path is headed NE into convection.. where tropical storm/gale force winds are been recored... see attached

one possible center near "16.8333N 57.2833W"

**note this is a low level invest mission... to find a "low".. if there is one... current flight level should have them less than 5 kft... as i wrote this... they turned around and are heading WSW now... so it appears the low center is near the above lat/long. pressure around 1007mb.. very weak and broad... will see what they keep finding.. do note... the highest winds are well to the NE of center

--------------------
www.Stormhunter7.com ***see my flight into Hurricane Ike ***
Wx Data: KFLPANAM23 / CW8771
2012== 23/10/9/5 sys/strms/hurr/majh



Edited by Storm Hunter (Tue Sep 01 2009 03:34 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Thunderbird12
Meteorologist


Reged: Thu
Posts: 644
Loc: Oklahoma
Re: HPC - Carribbean Forecast Discussion [Re: Storm Hunter]
      #86726 - Tue Sep 01 2009 03:58 PM

The most recent SHIPS guidance for 94L was initialized with an intensity of 45 kts, so this will be a Tropical Storm if it is determined to be a tropical cyclone:

http://www.srh.noaa.gov/productview.php?pil=WBCCHGHUR

This system could potentially affect the U.S. down the road, but it is going to have a hard time making it that far west without encountering quite a bit of shear.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ed DunhamAdministrator
Meteorologist & CFHC Forum Moderator


Reged: Sun
Posts: 2309
Loc: Melbourne, FL
Re: HPC - Carribbean Forecast Discussion [Re: Thunderbird12]
      #86727 - Tue Sep 01 2009 04:13 PM

As noted, NRL now lists the Invest at 45 knots and 1007MB. For site Users, this doesn't necessarily mean a TS - it just means that this was the initialization data used for model input.

From the NHC Glossary for Tropical Cyclone: "A warm-core non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and a closed surface wind circulation about a well-defined center."

I guess that the key word is 'organized' (which is not further defined). Even as a potential TD, the system is going to be problematic both for intensity and forecast track because of the strong southwesterly shear ahead of the system. Going to TD status doesn't solve those problems but at least the starting point will be defined (and perhaps even redefined at some future point). El Nino years often produce 'difficult' systems.
Cheers,
ED


Post Extras: Print Post   Remind Me!   Notify Moderator  
Storm Hunter
Veteran Storm Chaser


Reged: Wed
Posts: 1370
Loc: Panama City Beach, Fl. 30.16N 85.76W
Re: HPC - Carribbean Forecast Discussion [Re: Ed Dunham]
      #86728 - Tue Sep 01 2009 04:15 PM

Storm Location
Date: Sep. 1, 2009 18Z
Coordinates: 16.8N 57.2W
Wind Speed: 45 knots
MSLP: 1007 mb

the 18Z runs have TS... will wait to see

--------------------
www.Stormhunter7.com ***see my flight into Hurricane Ike ***
Wx Data: KFLPANAM23 / CW8771
2012== 23/10/9/5 sys/strms/hurr/majh



Post Extras: Print Post   Remind Me!   Notify Moderator  
Ed DunhamAdministrator
Meteorologist & CFHC Forum Moderator


Reged: Sun
Posts: 2309
Loc: Melbourne, FL
Re: HPC - Carribbean Forecast Discussion [Re: Storm Hunter]
      #86729 - Tue Sep 01 2009 04:31 PM

A special tropical suite model run by NHC indicated 18Z coordinates of 17.0N 57.0W for Tropical Cyclone Erika - so at least they are thinking about it.
ED


Post Extras: Print Post   Remind Me!   Notify Moderator  
Storm Hunter
Veteran Storm Chaser


Reged: Wed
Posts: 1370
Loc: Panama City Beach, Fl. 30.16N 85.76W
Re: HPC - Carribbean Forecast Discussion [Re: Ed Dunham]
      #86730 - Tue Sep 01 2009 04:37 PM

is it me... or did they do two/three Tropical suit runs... on 94L ?



--------------------
www.Stormhunter7.com ***see my flight into Hurricane Ike ***
Wx Data: KFLPANAM23 / CW8771
2012== 23/10/9/5 sys/strms/hurr/majh



Edited by Storm Hunter (Tue Sep 01 2009 04:38 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
scottsvb
Weather Master


Reged: Mon
Posts: 1096
Loc: fl
Re: HPC - Carribbean Forecast Discussion [Re: Ed Dunham]
      #86731 - Tue Sep 01 2009 04:38 PM

80% chance they will classify this...TD or TS...circulation is there..but the area is small in the NW winds dept...but still LLC is there...and winds are over 35kts.... so probably a TS.... they are probably just waiting on extra data before the plane leaves....probably come out within the next few minutes!

Post Extras: Print Post   Remind Me!   Notify Moderator  
MichaelA
Weather Analyst


Reged: Thu
Posts: 817
Loc: Pinellas Park, FL 27.83N 82.69W
Re: HPC - Carribbean Forecast Discussion [Re: Ed Dunham]
      #86732 - Tue Sep 01 2009 04:42 PM

Convection is getting closer to that location - becoming more vertically stacked? We'll see if NHC pulls the trigger at 5 PM ET or waits a bit longer. (17.0N; 57.0W)

--------------------
Michael
2014: 8/2/0
2014 Actual: 5/4/1

Edited by MichaelA (Tue Sep 01 2009 04:45 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Storm Hunter
Veteran Storm Chaser


Reged: Wed
Posts: 1370
Loc: Panama City Beach, Fl. 30.16N 85.76W
Re: HPC - Carribbean Forecast Discussion [Re: MichaelA]
      #86733 - Tue Sep 01 2009 04:49 PM

TCDAT1
TROPICAL STORM ERIKA DISCUSSION NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062009
500 PM EDT TUE SEP 01 2009

AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT HAS BEEN INVESTIGATING
THE LOW PRESSURE AREA EAST OF THE LEEWARD ISLANDS AND HAS FOUND A
MINIMUM PRESSURE OF ABOUT 1007 MB AND A CLOSED...ALBEIT...BROAD
CIRCULATION. PEAK FLIGHT-LEVEL WINDS WERE 52 KT WITH SFMR DATA OF
ABOUT 45 KT. THUS...TROPICAL STORM ERIKA HAS FORMED WITH AN
INITIAL INTENSITY OF 45 KT.


--------------------
www.Stormhunter7.com ***see my flight into Hurricane Ike ***
Wx Data: KFLPANAM23 / CW8771
2012== 23/10/9/5 sys/strms/hurr/majh



Edited by Storm Hunter (Tue Sep 01 2009 04:49 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ed DunhamAdministrator
Meteorologist & CFHC Forum Moderator


Reged: Sun
Posts: 2309
Loc: Melbourne, FL
Tropical Storm Erika Forms East of the northern Leeward Islands [Re: MichaelA]
      #86734 - Tue Sep 01 2009 04:50 PM

5:00 PM EDT Tue Sep 1
Location: 17.2°N 57.3°W
Max sustained: 50 mph
Moving: WNW at 9 mph
Min pressure: 1007 mb

Cheers,
ED


Post Extras: Print Post   Remind Me!   Notify Moderator  
Evan Johnson
Weather Guru


Reged: Fri
Posts: 143
Loc: Loxahatchee, FL 26.79N 80.28W
Re: Tropical Storm Erika Forms East of the northern Leeward Islands [Re: Ed Dunham]
      #86735 - Tue Sep 01 2009 04:55 PM

well the NHC pulled the trigger like we all figured as of 5pm update. seems like the model runs are agreeing on a more nw track. ill be curious to see if there are any westward tracks. i dont buy the nw movement yet.

Post Extras: Print Post   Remind Me!   Notify Moderator  
ftlaudbob
Storm Chaser


Reged: Tue
Posts: 757
Loc: Lauderdale-By- the- Sea,Fl 26.19N 80.10W
Re: Tropical Storm Erika Forms East of the northern Leeward Islands [Re: Evan Johnson]
      #86736 - Tue Sep 01 2009 05:18 PM

Well I was off by one day in pulling the trigger on Erica.I think we will have to wait till late tonight or till Wednesday for the models to get a handle on Erica.Right now they are all over the place.Some move the HIGH more west and block it from going north others do not.Erica is something to watch closely if you live on the east coast.This will be an interesting week.

--------------------

Survived:
Gloria,Bob,Katrina,Wilma and a bunch of tropical storms.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hugh
Senior Storm Chaser


Reged: Fri
Posts: 1060
Loc: Okaloosa County, Florida 30.51N 86.50W
Re: Tropical Storm Erika Forms East of the northern Leeward Islands [Re: Evan Johnson]
      #86737 - Tue Sep 01 2009 05:34 PM

Quote:

well the NHC pulled the trigger like we all figured as of 5pm update. seems like the model runs are agreeing on a more nw track. ill be curious to see if there are any westward tracks. i dont buy the nw movement yet.




Me either. The system is so weak and sheared, that should keep it on a western track. Of course, models forecast it to become a hurricane. The official forecast has it weakening despite the model forecasts, yet moving more NW in agreement with them... which seems odd to me.

Edit:
Well, over the last few hours it seems Erika has gotten much better organized, to be at least. There is a big blowup of convection where I thought the LLC was.


--------------------
Hugh

Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)


Edited by Hugh (Tue Sep 01 2009 06:21 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
berrywr
Weather Analyst


Reged: Fri
Posts: 370
Loc: Opelika, AL 32.71N 85.23W
Re: HPC - Carribbean Forecast Discussion [Re: Ed Dunham]
      #86743 - Tue Sep 01 2009 06:35 PM

Ed's right. I've been looking at the Visible Imagery over the last few hours and there is a closed LLC right on the western edge of convection. If you draw streamers, it's elongated but there. I'm fine with NHC pulling the trigger on Erika. I can't remember the last time a depression was called looking like this, but they had to have debated about this, but adhering to the strict definition it's at least a depression, so I'm cool with it. I found some Navy forecast wind shear data and the US is closed for tropical weather for at least the next 4 to 5 days. This is a tough call one way or the other. Who knows they could go back out there and not find a center and then what, post Gale force warnings, not Tropical Storm watches; what's the difference to someone who knows the wind is blowing rather stiff?

--------------------
Sincerely,

Bill Berry

"To work in the service of life and the living..." - John Denver


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hugh
Senior Storm Chaser


Reged: Fri
Posts: 1060
Loc: Okaloosa County, Florida 30.51N 86.50W
Re: HPC - Carribbean Forecast Discussion [Re: berrywr]
      #86745 - Tue Sep 01 2009 06:54 PM

Yeah, there's no real difference other than the fact that a tropical storm is likely to strengthen whereas an open gale wave is not likely to reach hurricane force winds (at least, I doubt it would).

--------------------
Hugh

Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Hawkeyewx
Weather Analyst


Reged: Sun
Posts: 63
Re: HPC - Carribbean Forecast Discussion [Re: Hugh]
      #86749 - Tue Sep 01 2009 07:28 PM

Brand new recon fix has the pressure down as much as 4 mb since the last fix two hours ago. It also found the center has moved slightly east of north.... which means the convection continues to try to suck it in.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Hugh
Senior Storm Chaser


Reged: Fri
Posts: 1060
Loc: Okaloosa County, Florida 30.51N 86.50W
Re: HPC - Carribbean Forecast Discussion [Re: Hawkeyewx]
      #86751 - Tue Sep 01 2009 07:48 PM

Quote:

Brand new recon fix has the pressure down as much as 4 mb since the last fix two hours ago. It also found the center has moved slightly east of north.... which means the convection continues to try to suck it in.




Interesting, I'm looking at the HDOBs and seeing very high pressures, but I also saw a 1004 in a vortex. It's definately looking a bit better on satellite.

--------------------
Hugh

Eloise (1975) - Elena and several other near misses (1985) - Erin & Opal (1995) - Ivan (2004)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | 5 | 6 | >> (show all)



Extra information
0 registered and 0 anonymous users are browsing this forum.

Moderator:  MikeC, Ed Dunham, danielw 

Print Topic

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled

Rating:
Topic views: 40000

Rate this topic

Jump to

Note: This is NOT an official page. It is run by weather hobbyists and should not be used as a replacement for official sources. 
CFHC's main servers are currently located at Hostdime.com in Orlando, FL.
Image Server Network thanks to Mike Potts and Amazon Web Services. If you have static file hosting space that allows dns aliasing contact us to help out! Some Maps Provided by:
Great thanks to all who donated and everyone who uses the site as well. Site designed for 800x600+ resolution
When in doubt, take the word of the National Hurricane Center