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Archives 2000s >> 2007 News Talkbacks

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MikeCAdministrator
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Disturbance off the Carolinas
      #77950 - Wed Sep 05 2007 08:20 AM

8:00AM EDT 6 September Update
Shear, the main thing preventing 99L from developing, will continue today, the upper level low that never backed off as predicted continues to tear up 99L, which looks more like a front than a tropical disturbance at the moment.

It still has a low level circulation, however, and if it manages to survive the windshear it then could develop, and meander a bit. Chances of it ever doing so are even lower than yesterday, however. It still may slide westward a bit, but it seems the models are just not handling this system very well, and it's not expected to amount to much, if anything.

Looking beyond 99L, there is not much else going on. So far this season has been lulls sprinkled with weak systems and two due west monster category 5 Caribbean Hurricanes. We still have the rest of September and October to get through, but so far the US has not had anything to deal with other than the flooding assisted by the weaker systems in Texas.



Chances for Tropical Development of Disturbance off Southeast Coast (99L) In Next 2 days
Code:

(forget it) 0 1 2 3 4 5 6 7 8 9 10 (sure thing)
[----*---------------]


11:05PM EDT 5 September Update
99L is still being sheared, and the 33% chance for development mentioned earlier still holds. It's looking more likely that it will not affect the mainland. If the circulation center survives the night, and the shear relaxes the chances for development go up. But it appears now that even through most of tomorrow, that won't be the case.

4:40PM EDT 5 September Update
Aircraft recon has flown into the disturbance off the coast (99L) and has found a circulation and released a vortex message with 33 knot flight level winds and a pressure of 1005mb.

Suggesting that a tropical or subtropical depression may be forming or has formed off the southeast. Advisories may begin as early as 5PM, but the system remains highly sheared this afternoon with the center of circulation mostly exposed so it's more likely tomorrow before it will form.

Models currently are very unreliable with this system, but if it forms, along with the new data from recon. We should have a slightly better picture with later model runs. However, slowly moving storms are usually very difficult to forecast and folks along the southeast would be advised to watch to see what happens with this system.

That said, it is still most likely that it will head out to sea.

Original Update
Hurricane Felix, now a depression, is spinning itself out over the mountains of Central America, bringing massive amount of rainfall and flooding to the area after making landfall yesterday.

Much closer to home, the disturbance off the east coast of Florida (99L) is still a bit of a wildcard. There are signs of it both being a tropical system and subtropical system (a hybrid low), the center itself seems to be exposed, and the shear is still high in so there isn't too much chance for development today, but it may later if convection occurs more around the center after the shear lets up.

Only could it then become a tropical or subtropical system. There is an off chance the center may reform under the convection too, and if that happens it will likely be more subtropical.


Chances for Tropical Development of Disturbance off Southeast Coast (99L) In Next 2 days
Code:

(forget it) 0 1 2 3 4 5 6 7 8 9 10 (sure thing)
[------*-------------]




The lack of any real steering currents in the area makes predicting the track hard, it could go anywhere from staying offshore and out to sea to affecting the Carolinas. Right now it's about a 50/50 split on it making landfall or not. More likely would be in the Carolinas. (GFDL and NOGAPS models tends toward South Carolina, while some of the others say North Carolina, yet more take it out to sea) If this happened it would be around the weekend. It's equally as likely (maybe even more likely) that it will move out to sea.

Since this hasn't developed yet it's just worth watching.

Where do you think this system will go? Will it develop? Let us know here in the forecast lounge.

More to come later...

Radar Loops
Melbourne FL Long Range Radar Loop (Latest Static) Base (Static) 1 HR Rainfall (Static) Storm Total Rainfall (Static)
Jacksonville FL Long Range Radar Loop (Latest Static) Base (Static) 1 HR Rainfall (Static) Storm Total Rainfall (Static)
Charleston, SC Long Range Radar Loop (Latest Static) Base (Static) 1 HR Rainfall (Static) Storm Total Rainfall (Static)
Wimington, NC Long Range Radar Loop (Latest Static) Base (Static) 1 HR Rainfall (Static) Storm Total Rainfall (Static)
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) Base (Static) 1 HR Rainfall (Static) Storm Total Rainfall (Static)

Various Caribbean Radio Stations

DR1 Dominican Republic Hurricanes
99L (Area off Georgia/Florida) Event Related Links

Flhurricane Satellite Floater Animation of of 99L - New for 2018


Animated Skeetobite Model Plot of 99L


stormplotthumb_8.gif

SFWMD Model Plot (Animated Model Plot) SFWMD Hurricane Page


float8latest.gif
Clark Evans Track Model Plot of 99L (Animated!) Model Plots in Google Earth - In Google Maps
Clark Evans Intensity Model Plot of 99L (Animated!)

Clark Evans Track Plot of 99L

Other Model Charts from Clark

Clark Evans Top 10 Analog Storms for 99L
More model runs on from RAL/Jonathan Vigh's page
NRL Info on 99L -- RAMMB Info

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


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nc_tropical_wx79
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Re: Disturbance off the Carolinas [Re: MikeC]
      #77951 - Wed Sep 05 2007 09:48 AM

looks like 99L has multiple vortices which is a sign of disorganization right? Just my opinion but it's satrting to look like the flight into 99l may not happen. On your scale from 1-10 what chance do you give 99L of becoming a TC?

--------------------
W.D. Duncan


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Ed in Va
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Re: Disturbance off the Carolinas [Re: nc_tropical_wx79]
      #77952 - Wed Sep 05 2007 09:54 AM

It's still fighting a lot of shear, which is supposed to relax. I don't think we'll know its fate until that happens.

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


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nc_tropical_wx79
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Re: Disturbance off the Carolinas [Re: Ed in Va]
      #77953 - Wed Sep 05 2007 10:04 AM

Dr. Masters has it as a subtropical depression already (in his blog) could it be subtropical and making the transition slowly because of the high shear? I've heard my local Met say he wouldn't be surprised if a new LLC forms under the convection and 99l starts to really take shape.

--------------------
W.D. Duncan


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invest1
Unregistered




Re: Disturbance off the Carolinas [Re: MikeC]
      #77954 - Wed Sep 05 2007 10:20 AM

It appears that on the vis sat loop that 99L is being sheared with winds from the sw. Does anyone see this happening because with the center exposed, the cloud masses looks to be blowing off the tops to the ne while the center itself is moving slowly due e. IMO if the shear does not slacken soon this system may go the way of 98L. Also have noticed the models are bouncing all over the place and I realize that it is not classified as of yet so models are not handling it well at this time, but what I'm still seeing is a lot of shear. Can anyone strighten me out!

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LoisCane
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Re: Disturbance off the Carolinas [Re: Unregistered User]
      #77955 - Wed Sep 05 2007 10:33 AM

Well, honestly the models are beginning to converge on an east coast hit so I believe the NHC will have to take it a little more seriously than they might otherwise.. as all I see is a nice low level swirl/center on visible that is too far east I think to make that dip down under the high and get pushed back towards land.

Unless ...the storm forms further south.. or moves further south.

But, with that many models turning back to the west.. you have to figure they see something we don't.

http://www.wunderground.com/tropical/tracking/at200799_model.html

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


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Tampa
Unregistered




Re: Disturbance off the Carolinas [Re: Unregistered User]
      #77956 - Wed Sep 05 2007 10:36 AM

I will say 2 things regarding intensity and track:

1. For intensity, the convection is very close to the LLC, so I believe
that once shear lessens, as the latest TWO says that conditions will become
more favorable, rapid strengthening is likely with a building ridge to the north.
Several models make this a hurricane and GFDL brings it to Category 2.
That is not impossible given the warmth of the gulfstream waters and the several
days this system has over the water.

2. As for track, I do not see this going out to sea. As we have seen with
Felix and Dean, the early long-range models out 3-5 days tend to
underestimate the ridge. Therefore, I think the track and model
consensus should shift substantially to the left, increasing
the threat to the carolinas, and depending on the ridge, possibly
even georgia or florida. This early in the forecast, you cannot rule
these areas out.

Convection as certainly been impressive, and it is likely to consolidate
closer and closer to the low level circulation as shear lessens.


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Steve H1
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Re: Disturbance off the Carolinas [Re: Unregistered User]
      #77958 - Wed Sep 05 2007 10:55 AM

I agree Tampa. This is a fairly strong vortex and once shear lessens, it should strengthen in short order (if shear lessens). I also believe that its reached its furthest east position now, and should begin a more westerly movement during late afternoon or tonight. This will be fun to watch, since models have shifted a bit to the left (even the 12Z NAM) and may be a sign that the ridge will stay entrenched over the east coast longer than anticipated last night. The EC and NOGAPS have this as a SC or GA hit. They initialized it a bit further west, but that may be negated by the fact that its a bit further south, and may actually drift a bit south while making the turn westward. Hopefully, the SE will get some much needed rain out of this without too much wind. Cheers!!

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MikeCAdministrator
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Re: Disturbance off the Carolinas [Re: Steve H1]
      #77960 - Wed Sep 05 2007 11:02 AM

The positive factors for development I really didn't mention before are the fact that there is a rather strong low level circulation, and the Dvorak T numbers actually support a tropical system now. But it still is incredibly sheared. Thankfully Recon will be out there soon enough to help make that determination.

The shearing, exposed center, and water vapor satellite loops show a huge negative for development, and that's why it's about 33%. Right now I don't think much of 99L. Tomorrow, however..


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Storm Hunter
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Re: Disturbance off the Carolinas [Re: MikeC]
      #77961 - Wed Sep 05 2007 11:28 AM

just an update on the aborted recon flight from the other day.

N42RF flew a 3D Doppler Winds experiment into Hurricane Felix. It left St. Croix, USVI at 04:00 PM AST, and it recovered at St. Croix, USVI at ??? ADT. Mission was aborted due to it encountering graupel and severe turbulence.

More to come.

As for 99L... looks to me its drifting to the ENE on vis sat this morning... the low level is exposed... Alot of shear.

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



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doug
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Re: Disturbance off the Carolinas [Re: MikeC]
      #77962 - Wed Sep 05 2007 11:32 AM

My thoughts exactly as expressed in the other thread yesterday...the only change I see today is some convection on the NW which did not exist yesterday...that certainly is consistent with increasing development...the longer it hangs around... I'm still at 3 on the analog scale.

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


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teal61
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Re: Felix [Re: WeatherNut]
      #77966 - Wed Sep 05 2007 01:28 PM

Was just looking at a vis loop of the remains of Felix . It appears that he has taken a turn to the NW. If you run the loop from the NOAA site with the wind overlay you can see the spin in the Caribbean just offshore Guatemala and just south of Belize. The wind barbs also seem to confirm this. Also went to the NASA site and did a "super" zoomed in loop of the same area and the weak circulation shows up pretty well.

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CDMOrlando
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Re: Disturbance off the Carolinas [Re: MikeC]
      #77967 - Wed Sep 05 2007 02:46 PM

MODEL DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP

DEVELOPING CYCLONE OFF THE SOUTHEAST COAST...

THE NAM IS FURTHER TO THE S AND W THAN THE GFS THRU MUCH OF THE
PERIOD AND IS AROUND 25 MB DEEPER AT THE SFC BY THE END OF DAY 2.
THE 00Z ECMWF/12Z CMC/UKMET GLOBAL ARE FASTER THAN THE NAM TO
CARRY THE SYSTEM WWD...BUT THE ECMWF SOLUTION IS DISCOUNTED GIVEN
THAT ITS 12HR FORECAST SHOWED A POSITION WELL WEST OF WHAT WAS
OBSERVED AT 12Z...WHILE THE CMC/UKMET INITIALIZED THE SYSTEM TOO
FAR W AS WELL. GIVEN THE POOR INITIALIZATIONS OF THE MODELS...DO
NOT HAVE A GREAT DEAL OF CONFIDENCE IN ANY PARTICULAR
SOLUTION...

BUT IN COMPARISON TO THE REMAINING MODELS THE GFS
APPEARS TOO WEAK WITH THE MID LVL RIDGE TO THE N OF THE SYSTEM AND
IS THEREFORE TOO SLOW TO MOVE THE SYSTEM WWD...WHILE ALLOWING THE
SYSTEM TO MOVE TOO FAR TO THE N. A MORE PROGRESSIVE/AMPLIFIED/SLY
SOLUTION THAN THE GFS WOULD BETTER FIT THE MODEL CONSENSUS. NOT
READY TO BUY INTO A SOLUTION AS PROGRESSIVE AS THE ECMWF GIVEN ITS
POOR FORECAST OR THE CMC/UKMET GIVEN THEIR POOR INITIALIZATIONS.

NOT SURE A SYSTEM AS DEEP AS THE NAM IS IN ORDER EITHER GIVEN ITS
TENDENCY TO OVER-AMPLIFY ANY SYSTEM OF A TROPICAL NATURE. THAT
SAID...THE CURRENT HPC/TPC THINKING IS FOR A TRACK FURTHER TO S
AND DEEPER THAN THE GFS...BUT NOT QUITE AS PROGRESSIVE AS THE CMC
GLOBAL/UKMET/00Z ECMWF.

THERE ARE ALSO ISSUES WITH THE STRENGTH/WRN EXTENT
OF THE MID LVL RIDGE OVER THE WRN ATLC AND ERN/SERN CONUS.
TELECONNECTION-FAVORED UPSTREAM CONFIGURATION FAVORS A HEALTHY
SERN RIDGE CLOSER TO WHAT IS DEPICTED IN THE ECMWF/RECENT NCEP
MEANS/06Z-12Z GFS. GUIDANCE CONTINUES TO SHOW THE POTENTIAL FOR
LOW PRESSURE OFF THE SERN COAST TO DEVELOP AND LIFT NWD ALONG THE
EAST COAST. THE 12Z GFS HAS SHIFTED NOTICEABLY WWD TOWARD THE
DOMINANT CLUSTER OF OTHER MODEL GUIDANCE.

FINAL MANUAL FCST http://www.hpc.ncep.noaa.gov/medr/day3nav.html

DEPICTS THE HPC/TPC COORDINATED TRACK FOR THIS FEATURE.


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LoisCane
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Re: Disturbance off the Carolinas [Re: CDMOrlando]
      #77969 - Wed Sep 05 2007 03:44 PM

How come there is no discussion of the GFDL. Is that normal or just for this system?

I'm a little confused on that one.

Aren't the planes in the system by now? Where are they flying out of.. if anyone knows?

http://www.wunderground.com/tropical/tracking/at200799_model.html

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


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MikeCAdministrator
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Re: Disturbance off the Carolinas [Re: LoisCane]
      #77970 - Wed Sep 05 2007 03:49 PM

Quote:

How come there is no discussion of the GFDL. Is that normal or just for this system?

I'm a little confused on that one.

Aren't the planes in the system by now? Where are they flying out of.. if anyone knows?

http://www.wunderground.com/tropical/tracking/at200799_model.html




The aircraft are in there now, and they found some pretty good winds (around 33-34knots), but with it still attached to the front a bit, and the convection sheared off like it is, I doubt the NHC will upgrade it to a depression tonight. Tomorrow, however, is a different story.


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craigm
Storm Tracker


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Re: Disturbance off the Carolinas [Re: CDMOrlando]
      #77971 - Wed Sep 05 2007 04:02 PM

99L has a very impressive LLC. When the shear lets up the system should start building vertically. The dynamics can really be seen in this loop with bursts of convection above the coc being sheared to the NE

http://www.ssd.noaa.gov/goes/flt/t3/loop-rgb.html

--------------------
Why I'm here:
Weather Junkie


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MikeCAdministrator
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Re: Disturbance off the Carolinas [Re: craigm]
      #77974 - Wed Sep 05 2007 04:38 PM

Recon release a vortex message, 1005mb, 33 knot flight level winds. It'll be a pure judgment call for the NHC to upgrade or not at 5PM, although this leans more toward tropical rather than subtropical. If it were up to me I would not upgrade it right now.

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DJINFLA
Weather Watcher


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Re: Disturbance off the Carolinas [Re: MikeC]
      #77975 - Wed Sep 05 2007 04:42 PM

Here's what the Indian River County Emergency Office sent on its email weather update a few minutes ago:


"Hurricane recon aircraft investigating satellite investigation 99L this afternoon have found a well defined closed circulation and surface winds near tropical storm strength. It is likely that the National Hurricane Center will upgrade this system to either Tropical Depression Seven or Tropical Storm Gabrielle at 5:00 p.m. This afternoon’s computer guidance has had a more westerly trend for the projected path of this developing system. However, it appears that most of the models have not initialized the system in the correct location. Once the data from the hurricane hunters is ingested into the model runs, it will be interesting to see if the westerly trend continues. In any event, climatology would dictate a track to the north, but we will need to pay attention just in case. I will continue to monitor and advise as needed."

May it just pull a Kyle from a few seasons ago and meander around the Atlantic spinning up fish before it dies!


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nc_tropical_wx79
Weather Guru


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Re: Disturbance off the Carolinas [Re: DJINFLA]
      #77977 - Wed Sep 05 2007 05:43 PM

Ummm DJINFL there was no upgrade at 5pm? Honestly didn't really expect one because looking at this invest I still say IMHO that dry air and shear will keep it just that 99L. Even with the trough forecast to move away and to it's north I still say too little too late and it's moved so far to the east I'm doubting it gets named/recognized and starting to doubt it's impact/landfall on the SE coast/US period. I'd give 99l on the scale a 1.5 maybe 2.

--------------------
W.D. Duncan


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Ed in Va
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Re: Disturbance off the Carolinas [Re: Unregistered User]
      #77981 - Wed Sep 05 2007 09:07 PM

99L looks very ragged tonight. I'm not sure it's going to survive. Does anyone have any specifics on when the shear is supposed to lessen?

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


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BillD
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Re: Disturbance off the Carolinas [Re: DJINFLA]
      #77982 - Wed Sep 05 2007 09:51 PM

From the TWD issued at 8:05 PM

A NON-TROPICAL AREA OF LOW PRESSURE LOCATED ABOUT 320 NM
WEST-SOUTHWEST OF BERMUDA NEAR 30N70W...ANALYZED 1008 MB...HAS
GENERALLY CHANGED LITTLE IN STRUCTURE. ... HURRICANE
HUNTER AIRCRAFT INDICATE THAT THE LOW HAS NOT YET ACQUIRED THE
CHARACTERISTICS OF A SUBTROPICAL OR TROPICAL CYCLONE.

FWIW, several of the models are developing something out of this, but no mention of that in the discussion.

Bill


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typhoon_tip
Meteorologist


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Re: Disturbance off the Carolinas [Re: BillD]
      #77984 - Thu Sep 06 2007 12:46 AM

Quote:

From the TWD issued at 8:05 PM

A NON-TROPICAL AREA OF LOW PRESSURE LOCATED ABOUT 320 NM
WEST-SOUTHWEST OF BERMUDA NEAR 30N70W...ANALYZED 1008 MB...HAS
GENERALLY CHANGED LITTLE IN STRUCTURE. ... HURRICANE
HUNTER AIRCRAFT INDICATE THAT THE LOW HAS NOT YET ACQUIRED THE
CHARACTERISTICS OF A SUBTROPICAL OR TROPICAL CYCLONE.

FWIW, several of the models are developing something out of this, but no mention of that in the discussion.

Bill




They won't do that, pretty much ever. There is no purely tropical model beyond statistical based guidance..which does purely tropical physics. Everything is either baroclinic [meaning, based on horizontal differentiable medium] or limited-scaled baroclinic at best, and that means that inherently, they are prone to inaccuracies, particularly during the genesis phase.

No one want's to "officiate" a statement based on inherently erroneous tools. So it is understandable policy that they mention model coverage only after a system is already trackable. The reason why is because storm genesis outside the tropics is physcically different, in that it is based on fluid mechanics combined with temperature and dp gradients across that fluid medium. In the tropics, however, the quadrants are even -- typically -- and the only engine is the thermodynamics in the vertical, such that a coupled oceanic heat content with the lower atmosphere provides an abundance of convective available potential energy to rising parsels.

When you have a cyclonic curvature at upper levels of that which is observable this night impacting the area, this creates a medium conducive to extra-tropical cyclogensis. I have not been stellar in my own anticipations of this system evolution thus far.. I did not foresee this trough establishing its self with this strength. The overal picture has changed toward one which will take a long time if ever, to become tropical entity.


Edited by typhoon_tip (Thu Sep 06 2007 01:06 AM)


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typhoon_tip
Meteorologist


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Re: Disturbance off the Carolinas [Re: Ed in Va]
      #77985 - Thu Sep 06 2007 01:21 AM

Quote:

99L looks very ragged tonight. I'm not sure it's going to survive. Does anyone have any specifics on when the shear is supposed to lessen?




Good question! This is instrumental in this system's future. The shear was not very well modeled.

There has been strong diurnal convection in the lower Mississippi Valley the last 2 days and this is fluxing convective heat release into the atmosphere in the area and into the SE U.S. That raises heights because of the heat insert causing an expansion of the medium -- like filling a balloon. But there is no rubber boundary in the atmosphere so the expansion causes the wind to increase as it flows outward from areas of expansion to areas of less pressure. The result is an increase in the ridge intensity over the SE, which causes increases wind flow into the weakness off the SE Coast. The trough appears stronger than modeled, because the models ultimately have not been handling the consequence of latenet heat release of convection in the deep south over the Mississsippi Valley very well.

I believe this is the cause for the trough digging into 75W and ultimately the shear stress on the system.


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nc_tropical_wx79
Weather Guru


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Re: Disturbance off the Carolinas [Re: typhoon_tip]
      #77986 - Thu Sep 06 2007 01:36 AM

I'm sorry I didn't understand none of that! So will the shear lessen soon or around what time and is it safe to write off 99L as a tropical entity now?

--------------------
W.D. Duncan


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BLTizzle
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Re: Disturbance off the Carolinas [Re: nc_tropical_wx79]
      #77987 - Thu Sep 06 2007 03:06 AM

I believe he is referring to radiational cooling. For instance, if you pour salt on a table and stand directly over it and blow on it, its going to spread out into a circle. Picture the air over the southeast as the salt, and the atmosphere as the table, when the heated air hits the atmosphere, it spreads out, thus adding shear to 99L. Since the heated air has nowhere to go once it escapes the lower levels, it has go be distributed evenly.

Hope that helped

--------------------
Brandon in Eufaula, AL - experienced TS Alberto ('93) Opal ('95), Georges ('98), Ivan ('04), Katrina ('05) (I was in Tuscaloosa AL roughly 70 miles SSE of Columbus, MS)


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HanKFranK
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Re: Disturbance off the Carolinas [Re: punkyg]
      #77989 - Thu Sep 06 2007 07:37 AM

that upper low, which was poorly foreseen and highly underestimated in just about all the modeling, laid 99L flat. the system is finally 'blocked', i.e. track is bending south and should turn west shortly. at the same time that upper low hasn't cut off, or moved west of the system, or done any of the things that would have lessened shear. 99L behaved more like a frontal low, clinging to the western side of the upper low, and has now lost much of its definition and convective activity as the induced baroclinic conditions subsided.
all of the models are out to lunch. if anything survives this (which has longer odds now, with all the subsidence to fight and so little definition) the near unanimous contention that it will latch onto the first shortwave and recurve near north carolina is probably also out to lunch. for whatever remains, i'd expect it to sort of jerk and bob around in weak steering, working slowly westward under the ridge while it lasts. otherwise, the near tropcial cyclone we had the other day is a wash.
eastern atlantic has nothing to offer. massive, well-defined waves with no convection are cans of corn. the upper low cutting off southeast of newfoundland has a better chance than the big wave near 45w. modeling develops another storm later, but all recurve it well off out to sea.
the ominous look of things a couple days ago is evaporating. if 99L smears out completely and never gets out from under the shear, we're into another lull.
season so far has been defined by long periods of nothing between weak storms, and huge category fives barreling west across the caribbean.
HF 1137z06september


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invest1
Unregistered




Re: Disturbance off the Carolinas [Re: HanKFranK]
      #77990 - Thu Sep 06 2007 08:06 AM

I agree. Even yesterday it did not look all that impressive due to a lack of moisture around the center. My question is, it appeared to have moved a little s over night and looks to be trying to wrap some moisture around, albeit very little, could this thing servive and if it did with all the dry air around how much of an impact would the gulf stream have on it if any?

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hurrev
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Re: Disturbance off the Carolinas [Re: Unregistered User]
      #77992 - Thu Sep 06 2007 10:10 AM

Looking at the vis sat loop, 99L seems to be as good as it did yesterday and seems to be pulling away from the front. I also noticed that the 06Z GFDL seems to be more impressed with the development than the 00Z model output seemed. At 00Z GFDL had it going in around Wilm NC with 60 mph and 06Z now has it in Wilm with 95 mph. Am I reading this model correctly because by no means am I a met!

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Ed in Va
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Re: Disturbance off the Carolinas [Re: Unregistered User]
      #77993 - Thu Sep 06 2007 10:16 AM

You are correct in your reading of the model, but I believe the wind speed is measured above the surface and is therefore stronger than the actual on land. In interpreting models, look for consistency over time, not just a comparison of two consecutive ones.

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


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typhoon_tip
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Re: Disturbance off the Carolinas [Re: MikeC]
      #77997 - Thu Sep 06 2007 12:11 PM


I agree with the 8:00am update:

http://flhurricane.com/cyclone/showflat....SSID=#Post77996


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allan
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Re: Disturbance off the Carolinas [Re: MikeC]
      #77998 - Thu Sep 06 2007 01:04 PM

99L looks like it is now cutting off from the frontal mess.. all of that will head out to see as the little swirl (99L), is now moving or even slowly drifting south into favorable shear, I expect this system to get much better organized in structure and convection by tommorrow morning.. the forecast track (so far, anything can change beyond that) is much like Gustav in 2002. After 94L (Felix) I am not writing this storm off yet.. looks to be pulling away from the trough that is tearing it apart.. and some tiny indications of storms around this swirl.
http://hadar.cira.colostate.edu/ramsdis/online/trop_ge_storm_relative_1.html

--------------------
Allan Reed - 18,9,5

Edited by allan (Thu Sep 06 2007 01:09 PM)


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hurrev
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Re: Disturbance off the Carolinas [Re: allan]
      #78001 - Thu Sep 06 2007 08:31 PM

Just noticed that the GFDL is still showing 06Z. have they stopped running models on 99L?

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Lee-Delray
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Re: Disturbance off the Carolinas [Re: Unregistered User]
      #78002 - Thu Sep 06 2007 08:36 PM

They stopped covering 99l earlier today. At this time there doesn't seem anything to cover.

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nc_tropical_wx79
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Re: Disturbance off the Carolinas [Re: Lee-Delray]
      #78005 - Thu Sep 06 2007 09:23 PM

If you look at 99L now it looks like convection is trying to start building over the LLC so it may still have a chance yet.

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W.D. Duncan


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Bastardicasting
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Re: Disturbance off the Carolinas [Re: nc_tropical_wx79]
      #78008 - Thu Sep 06 2007 10:28 PM

(Wishcasting is not permitted on this site - post deleted.)

Edited by Ed Dunham (Fri Sep 07 2007 08:19 AM)


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scottsvb
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Re: Disturbance off the Carolinas [Re: Unregistered User]
      #78009 - Thu Sep 06 2007 10:33 PM

lol now that is JB talking...haha soo funny. Actually 99l is straight on forecast (besides strength) Im beginning to wonder though how far south that trough will dig and if the ridge over the deep south will slide to off the mid-atlantic and SE early next week.

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typhoon_tip
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Re: Disturbance off the Carolinas [Re: HanKFranK]
      #78010 - Thu Sep 06 2007 10:47 PM

Quote:

that upper low, which was poorly foreseen and highly underestimated in just about all the modeling, laid 99L flat. the system is finally 'blocked', i.e. track is bending south and should turn west shortly. at the same time that upper low hasn't cut off, or moved west of the system, or done any of the things that would have lessened shear. 99L behaved more like a frontal low, clinging to the western side of the upper low, and has now lost much of its definition and convective activity as the induced baroclinic conditions subsided.
all of the models are out to lunch. if anything survives this (which has longer odds now, with all the subsidence to fight and so little definition) the near unanimous contention that it will latch onto the first shortwave and recurve near north carolina is probably also out to lunch. for whatever remains, i'd expect it to sort of jerk and bob around in weak steering, working slowly westward under the ridge while it lasts. otherwise, the near tropcial cyclone we had the other day is a wash.
eastern atlantic has nothing to offer. massive, well-defined waves with no convection are cans of corn. the upper low cutting off southeast of newfoundland has a better chance than the big wave near 45w. modeling develops another storm later, but all recurve it well off out to sea.
the ominous look of things a couple days ago is evaporating. if 99L smears out completely and never gets out from under the shear, we're into another lull.
season so far has been defined by long periods of nothing between weak storms, and huge category fives barreling west across the caribbean.
HF 1137z06september




Hank',
this may not be the time nor place but I get a somewhat different vibe than you concerning the TW that has just come off near Sierra Leone. Significant cyclonic turning with an approximate lat/lon axis near 22W/9N and ongoing moderate to strong convection contained.

John

(Just a reminder to all that comments on the latest wave off of Africa are better suited to another Forum since this wave was not mentioned in the Main Page leadoff article.)

Edited by Ed Dunham (Fri Sep 07 2007 08:25 AM)


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Ed in Va
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Re: Disturbance off the Carolinas [Re: nc_tropical_wx79]
      #78012 - Thu Sep 06 2007 11:39 PM

Agreed, but maybe only looks better now because it looked some horrible earlier...still has a long ways to go.

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


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John Mellonhead
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Re: Disturbance off the Carolinas [Re: Ed in Va]
      #78013 - Fri Sep 07 2007 02:44 AM

Far from a pro here, but enjoy the site. Haven't checked in since getting whacked around in S. Florida a few years ago.

Anyway, is it just me or is the GFDL looking bang on? Looks like a clear circulation with some action cropping up now, and reverse throttle seems to have been thrown down. Does "Gabby" have basically a clean runway right into South Carolina at this point?

Thanks again for an informative website.


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Marcus
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Re: Disturbance off the Carolinas [Re: John Mellonhead]
      #78014 - Fri Sep 07 2007 05:21 AM

Quote:

Far from a pro here




Same here, I just like looking at the satellite pictures I 'spose .

From what I've seen, 99 just keeps trying and trying; for myself, who knows little about weather patterns in general, it's been a perfect example of how wind shear can affect the formation of a storm, and how dry air can affect progression, so it's been very informative from that respect. For the last couple of days I haven't been able to see much reduction in the circulation, so if this shear does drop it might still have something of a chance. Unfortunately, my ability to read weather to know whether that's likely is pretty non-existent... what should I be looking for and from what information source will I be able to determine if/when that shear will end?


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