danielwAdministrator
(Moderator)
Sat May 26 2007 04:06 AM
Memorial Day Weekend Area to Watch

The GFS model and a few of the other models have been hinting at a possible Tropical system forming in the Western Caribbean. Hit and miss in the model runs for the last 7 days.

The Caribbean Forecast Discussion has been hinting at an Eastern Pacific system... possibly crossing Central America and moving into the Caribbean Sea.
Again, just an honorable mention in the discussions.

While I haven't checked the surface observations. The preliminary satellite observations would certainly suggest that minimal wind shear is present at 4 AM EDT-Saturday. (08Z)

This is an image that was posted on the morning of May 20th. A 216 hour forecast!



And this link displays the latest rainbow enhancement of the area.
Rainbow Enhancement GOM and W Caribbean

Main Page for the SSD satellite products is here.
NOAA SSD Tropical Satellite Page


Rich B
(British Meteorologist)
Sat May 26 2007 10:16 AM
Re: Memorial Day Weekend Area to Watch

Ok, a quick check of visible imagery shows a low pressure area may be developing near 80W 13.2N. Additionally, the 06Z surface analysis shows a new low pressure area in this area. As for model support - well the 00Z run of the NOGAPS picked up on a developing low pressure system from 00Z this evening, lasting through Thursday and moving generally towards the northwest. It is kept as a marginal warm-core system, so a possible tropical cyclone. Given the abundant convective activty in he region, and the model hints recently, it is certainly worth keeping an eye on this area.

dem05
(User)
Sat May 26 2007 11:45 AM
Re: Memorial Day Weekend Area to Watch

The last 3 runs of the NAM have been pretty consistent and fairly robust too...

00Z Link: http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/nam/00/index_slp_s_loop.shtml
06Z Link: http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/nam/06/index_slp_s_loop.shtml
12Z Link: http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/nam/12/index_slp_s_loop.shtml

This might get a little interesting...


Clark
(Meteorologist)
Sat May 26 2007 12:32 PM
Re: Memorial Day Weekend Area to Watch

Models are pretty consistent in terms of *something* down that way and truthfully have been for a few days now. As HF might point out, it fits the Joe Bastardi test of lower pressures across the region. The MJO (upper level wind fields) are somewhat favorable for this time of year as well from the perspective of getting deep convective development. What is there now is sorta in a "bubble" region, i.e. if it goes too far in any direction it either hits less favorable winds or land.

I do urge a little caution with this, however, in particular if the GFS is used with respect to any developments down there. At the start of May, some changes were made to the GFS to hopefully improve its prediction with the formation and intensification (representation) of tropical systems. Unfortunately, it appears that these changes have gone too far and have returned the model to the days of the late 1990s where *everything* coming off of Africa became a tropical system. (Anyone else remember those days? ) Skill scores for the model in the 5-10 day time period, a measure of how well the model verifies, have dropped dramatically since the new GFS code was implemented -- partially due to negative feedbacks from the tropics, I feel.

That said -- there is some support for this in the actual observations and from the other models, so it bears watching. Yesterday's 12z and today's 00z runs of the European model seem to want to feed this energy into the Gulf of Mexico in 6 days' time or so and then into Florida and the southeast as a rain storm associated with a non-tropical area of low pressure. It's a setup more common of February-March than early June, but it's also a setup that can help bust a drought...and one that if there is something tropical out there beforehand could be a more significant event. Tropical or not, it all bears watching over the next week.


danielwAdministrator
(Moderator)
Sat May 26 2007 02:33 PM
Quick Update

Several of todays Discussions are mentioning the area in the Western Cariibean.
Latest Trop Weather Discussion also.
Extended outlook for the week ahead from HPC here:
Extended Outlook Wednesday thru Saturday

Visible satellite imagery indicates a broad area of Low pressure from W Cuba toward the Isthmus of Panama.
GHCC MSFC NASA Satellite site for Caribbean

241pm EDT
Appears to be a mid to upper level Low forming just North of the Bay of Campeche. Along 22N/ 95W.
GHCC Visible satellite site with zoom


cieldumort
(Moderator)
Sat May 26 2007 05:54 PM
Re: Memorial Day Weekend Area to Watch

Coming in a little late to just to add that SSD now has Floater 3 up over "Invest" located near 12.5N 78W.

Broad circulation evident in that moderate to low-moderate shear environment, with some pretty decent low-level convergence taking place into a particularly healthy convective cluster at the center of a vortice (12.5N 78W).



Tony Cristaldi
(NWS Meteorologist)
Sat May 26 2007 06:11 PM
Re: Memorial Day Weekend Area to Watch

IMHO things are about to get very interesting for Florida. I touched upon it in my afternoon AFD, but I have a little time to expand on these thoughts, so here goes.

First thing to mention is that the pressures are usually fairly low in the western Caribbean, and today is no exception. I noticed some buoy/ship ops around 1010MB in that general area. Second, there are two well defined vortices in the CU field noticeable on vis imagery. The first is east of the Yucatan (18N 87W) and the second is east of Nicaragua (12.5n 80W). The one east of Nicaragua looks a little tigher and has more in the way of convection near the center, plus a huge slug of deep tropical moisture/convection to it's east.

(better to view the link below if you have broadband and a large monitor, or simply change the height/width to 600/600)

http://wwwghcc.msfc.nasa.gov/cgi-bin/get...p;mapcolor=gray

What gets really interesting is the change in the synoptic pattern over the GOMEX over the next several days. If you'll allow me to cannibalize my own AFD...

XTD...AS HAS OFTEN BEEN THE CASE IN THE PAST...THE 12Z GFS HAS TRENDED DECIDEDLY TOWARD THE LAST SEVERAL RUNS OF THE ECM AT H50...W/R/T BOTH THE MORE PROGRESSIVE NRN STREAM...AND MORE IMPORTANTLY...H50 HEIGHT FALLS MOVING INTO THE GOMEX FROM MID WEEK ONWARD...WHICH MAY BE A HARBINGER OF SOME FAIRLY DECENT CHCS FOR SOME MUCH NEEDED RAINFALL FROM DIURNAL CONVECTION BY LATE NEXT WEEK.

and...

MED RANGE MODEL GUIDANCE SUGGESTS AN INCREASING CHANCE FOR A MUCH NEEDED WIDESPREAD/HIGH COVERAGE RAIN EVENT LATE NEXT WEEK AS WE HEAD INTO JUNE. CONTINUED AMPLIFICATION OF THE WEAK SRN STREAM TROUGH IS PROGGED TO OCCUR OVER THE GOMEX BY BOTH THE 00Z ECM AND 12Z GFS. ECM IS MUCH MORE ROBUST WITH BOTH THE H50 TROUGH...AND THE SURFACE RESPONSE...HOWEVER BOTH SOLNS SHOW ENOUGH AMPLITUDE TO ALLOW DEEP LYR FLOW TO ACQUIRE SIGNIF SRLY COMPONENT TO ADVECT DEEP TROPICAL MOISTURE NWD INTO FL. BY FRI/SAT...THE ECM SHOWS A MORE CUTOFF/SLOWER SOLN...WHILE THE GFS LINKS THIS WEAKNESS UP WITH THE NRN STREAM...CREATING A BROADER MORE FULL LATITUDE TROUGH. IT`S HARD TO IGNORE THAT THE GFS HAS OFTEN FOLLOWED THE ECM`S LEAD WITH THE CURRENT PATTERN...AND IT IS ENCOURAGING TO SEE BETTER AGREEMENT BTWN THE TWO...THOUGH IT STILL IS IN THE DAY 4+ TIME FRAME. SO CAN`T
BITE OFF ON THESE SOLNS UNTIL CONTINUITY IS BETTER ESTABLISHED. FOR NOW HAVE GONE JUST A LITTLE MORE BULLISH FOR POPS THU...AND KEPT SCT SHRA/TSRA IN THE FCST FOR FRI/SAT.

Adding onto that is the fact that the 12Z ECM continued to be much stronger at H50 and with the surface low coming up out of the Caribbean.

So, we have
(1) low pressure in the area
(2) a fairly healthy low level vortex already down there sitting and spinning
(3) a loose model consensus for "something" to form from the ECM/UKM and GFS (in spite of the return of it's horrible convective feedback problem and resultant low spin-up-o-rama)

This is where it gets interesting. Significant height falls at 500 MB will occur over the western GOMEX and gulf coast starting TUE, and responsible trough will work eastward toward Florida from mid to late next week.

Going back to my AFD, The ECM is deeper, so much that it looks like it's weakly cutoff at 500MB. The surface evolution looks a little strange in that the 500MB low actually captures the surface system coming out of the Caribbean. We wind up with a 1001MB low getting propelled northward into the FL panhandle.

On the other hand, the GFS takes the distinct southern stream 500MB feature eastward, but it gets captured and absorbed into the base of the northern stream trough, making it nearly full latitude. It's surface low, which looks like it's from convective feedback, forms farther east and turns more quicky across extreme SE Florida and then out to sea.

I have no strong opinion on which model to favor at this point, other than noting as I did in my AFD that the GFS has been following the ECM's lead up until now. I think there will be quite a bit of interest for Florida folks over the next several days.

Tony C.

edit: On more note - It's still only may and the ST Jet will stay pretty strong between 25 and 30N. That would argue for something not purely tropical, or a system morphing into a "sloppy, right-sided, hybrid, baroclincally enhanced thingamajiggy" (for lack of a better term)


HURRICANELONNY
(Weather Guru)
Sat May 26 2007 06:19 PM
Re: Memorial Day Weekend Area to Watch

I THINK THE BOTTOM LINE FROM ALL THOSE MODELS IS RAIN FOR FLORIDA!

Probably true but lets refrain from one-line posting in this Forum. Thanks


Clark
(Meteorologist)
Sat May 26 2007 11:41 PM
Re: Memorial Day Weekend Area to Watch

Things look pretty interesting for late May down in the Southwest Caribbean...looks like a mid-level circulation has spun up with intermittent deep convection in place; QuikSCAT from yesterday evening even hinted at a weak low level circulation underneath the mid-level feature and the convection. Nice evacuation channel at upper levels into the central Atlantic in association with a weak upper low near the Bahamas and a trough to its northeast. Probably our next "invest" -- NHC's satellite page hints at that already on floater 3, in fact -- over the next day or so.

Most of the models hint at something heading in a general NW fashion over the next 3-5 days or so into the NW Caribbean and southern Gulf of Mexico, with the NAM and the ECMWF being the most bullish at this point. The projected weather patten into late next week is of a trough digging into the eastern United States; if that pans out, the system will generally want to head north and ultimately northeast. How fast something organizes down there -- if it does at all -- will help decide where it ultimately goes and potentially how fast it recurves. People in Florida and inland Georgia should watch this over the next few days, as even if nothing tropical organizes...it looks like it could bring some much needed rains.


LoisCane
(Veteran Storm Chaser)
Sun May 27 2007 08:17 AM
i see it Clark but...

it's having a hard time down there maintaining its color ... hints of something happening but nothing yet. Thanks for the loop. Maybe tomorrow... shear still needs to soften a bit. Looks better than yesterday, has a twist but the color keeps getting blown away

allan
(Weather Master)
Sun May 27 2007 08:57 AM
Re: i see it Clark but...

Morning everyone..
Got to make this quick cause I have church soon..
Here's what could and based on past experiences, what I believe will happen with what should of been 92L yesterday.
Everyone on wundergound blogs say it's weakening but little do they know that the same thing happened with Alberto before he blew up last year. It's going through a structual phase. It's trying take shape of a storm and convection is usually little when that happens. It could blow up at any tie now, probably most likely this afternoon. By tommorrow, TD2 may be brewing. CMC model scares folks in the Caolinas with a surprise Hurricane Barry in 144 hours. Lets not forget it was this model that was right on with Alberto. So lets wait and see before we make any death threats on this disturbance


typhoon_tip
(Meteorologist)
Sun May 27 2007 03:18 PM
Re: Memorial Day Weekend Area to Watch

A quick comment or two on the model outputs this Sunday morning...

As Clark was discussing and I concur; the GFS has been a bit zealous in spinning up any perturbation it can sniff out, into a meaningful tropical system this spring.

However, the Day 6 onward is interesting in the 12z ECM. The MSLP charts indicate an inverted V in the surface pressure pattern, with strong hints at cyclonic closure passing across the Panhandle of Florida by the end of Day 6. This offers some support to the prior GFS outputs.

Interesting to note that the 12z run has lost the signal for these days. The UKMET and Canadian models look more similar to the ECM so this particular GFS run appears to be an outlier... Note, the Canadian actually goes ahead develops the Atlantic season's first TC...eventually just NE of FL. The overall consensus is a little more interesting than this day's 12z GFS solution.

The deep layer shear appears to be favorable during that time period, as fairly strong antecedent ridging evolves and slowly progresses through 35N/80W, D3 - D6. That places the area of the Gulf and western Caribbean typically in a deeper layer easterly flow regime, while dropping the upper atmosphere wind velocities across these areas to light. Moreover, the trend has been to slow down the entire pattern evolution at these key latitudes, so that also somewhat prolongs this period of favorable deep layer winds, giving more time for whatever to evolve to go ahead and do so.. Because convection has had a propensity in recent days to linger and refire in that region of the western Caribbean, the establishment of any favorable governing pattern does warrant increased monitoring.

Without considering a more important intensification taking place, this all could go quite far toward adjusting the season rainfall deficits in the positive direction, going from famine to feast. This can bring a tremendous dose of obsenely high precipitable water values. ...So perhaps this would all be a good thing.

John


LoisCane
(Veteran Storm Chaser)
Sun May 27 2007 06:07 PM
Re: Memorial Day Weekend Area to Watch

Quote:

A quick comment or two on the model outputs this Sunday morning...

As Clark was discussing and I concur; the GFS has been a bit zealous in spinning up any perturbation it can sniff out, into a meaningful tropical system this spring.

Zealous? It's been like Superman on steroids trying to save the world

I think it can happen, but as a rainmaker or as a defined named system?

If other models jump on board .... if

typhoon_tip
(Meteorologist)
Sun May 27 2007 11:30 PM
Re: Memorial Day Weekend Area to Watch


They have, the models that is... come around to the "if". That was some of my point. The Canadian, UKMET and ECM have all formed some form of cyclonic tropical characteristic entity impacting Florida to some degree or another.


Rich B
(British Meteorologist)
Mon May 28 2007 05:18 AM
Re: Memorial Day Weekend Area to Watch

Indeed, model support is increasing for a system moving through the Yucatan Channel, then recurving into the Florida big bend area around the end of this week. The CMC is most bullish, taking quite an intense system into the big bend / panhandle on Friday, then keeping it inland and weakening. The UKMET model takes a broader, and somewhat weaker system across the central Florida west coast, moves it offshore near the FL / GA border, where it rapidly deepens before skirting the SC / NC coast. Again, the Florida landfall is around Friday, with the system affecting the Carolinas late this coming weekend. The GFS doesnt seem to give much support for either solution though at the moment!

allan
(Weather Master)
Mon May 28 2007 01:14 PM
Re: Memorial Day Weekend Area to Watch

The Carribean disturbance looks better this afternoon. A flare up is now in process over the "new" center which looks to be well east and a bit north of the old one. Since it's seperated from the upper level low now, I think we need to really keep an eye out for Barry sometime in a couple of days as it continues to brew out in over 80 degree temps and very low shear. The 12z CMC predicts it to develop in the GOM and head to the panhandal of Florida. haven't seen the 12z UKMET. Whats also interetsing is now the CMC develops another cyclone "Chantal" in the awake of "Barry" if you go by the run. So lets wait and see what happens, if a blow up occurs, it would be in the right part of the new center where storms are currently flaring.

Hurricane29
(Weather Guru)
Mon May 28 2007 01:40 PM
Re: Memorial Day Weekend Area to Watch

I think thats unlikely to happen more bluff from the cmc.I think barry will wait to the end of june or the begining of july.Also the trof in the central atlantic is creating unfavorable conditions over tha area at the moment.Dont expect that to change for now.

allan
(Weather Master)
Mon May 28 2007 01:49 PM
Re: Memorial Day Weekend Area to Watch

I tend to disagree, conditions in the western carribean are favorable for development. Just got to give it some time. If this disturbance didn't have potential, it would have been gone by now. It really is trying to get itself going. I see a good defined circulation with strong convection, small but it is there. Also, there is no way we are going to get Barry that late according to the current pattern. By July, we MAY be watching Dean or Erin.. really depends how bad this season wnats to get lol. I still stand on my prediction for 18/9/6.

scottsvb
(Weather Master)
Mon May 28 2007 02:28 PM
Re: Memorial Day Weekend Area to Watch

Well Tony the other day said probably what will happen as he is also a Met. I think right now the CMC is its usual self on being too agressive with tropical systems. The GFS goes downhill after 120hrs out...afterall (look above) on the 216hrs out..the gfs said there should be a strong 1001mb low entering the SE Gulf tonight..but its wayyy off. Nogaps tends not to pick up on everything at first..and the UKMet is usually alittle off base at times. Overall in the short term I like to use the GFS with the ECMWF for days 5-6.

Currently we have a weak low in the sw carribean. A trough is just south of jamaica with vort maxs spinning up as the trough iteracts still with the departing upper low to its N and the landmass backoff of Jamaica. I'm not sold on this being the main feature that the CMC is seeing. Its energy will combine with lower pressure from the pacific. In 36-48hrs a upper trough or cut off low will develop over the NW Gulf of Mexico. Energy from the trough in the NW carribean along with moisture from the EPAC will converge by Thurs-Fri near the Yucitan. With the upper trough digging in late in the week into the weekend..mositure or a low could form and head N or NE..

If anything I would be watching the low in the far E pac.


dem05
(User)
Mon May 28 2007 05:23 PM
Re: Memorial Day Weekend Area to Watch

Scott, your comments are not unreasonable. Based on my best "eyeball" of the satellite of the SW Carrib. this afternoon, there is a weak surface vorticity around 14N,79W and a weak mid level around 15N, 77.5W. Overall shear is not bad in the area and the surface and mid level features are approaching each other this afternoon. It would be interesting to see what would happen if these two features can "stack" under this lower shear environment.

A lot of us disagree with JB at Accu on many things, but one thing I learned 4 or 5 years ago from his streaming videos...and has played out well, is that a cut-off low or trough that is west of 90W in the Gulf/Texas region can really bode well for a low pressure system to develop/strengthen in the NW Carribean and Eastern Gulf. In the coming days, it will be interesting to see the timing. In the meantime, this area of weather has an opportunity to compose itself over the next few days under a lower shear environment.

As for the moisture tap that may give this "area" some extra needed punch over the next few days, I prefer to look downstream at Northern South America. If a couple good impulses could come along the ITCZ from South America and pile upon this "area", then it has a better shot. Looking at past systems to develop, I give that opportunity a higher percentage than the opportunity of something breaking free fromthe ITCZ on the Pacific side and coming north. With that said, if you are hopeing for some good impulses coming in from South America, I've seen much better circumstances and I don't see anything overly eye popping down there now though.

As for the models, I will repeat something that has been said here before, they are difficult to deal with when it comes to early season development/cyclogenesis in the tropics. Also, they sometimes miss a beat when it comes to picking up on a developing system. In past seasons, I have seen the models develop a nasty hurricane that never ended up happening. Likewise, I've seen systems develop when the models gave no indication.It is that time of year, and if you are strongly leaning on the models providing a strong consensus/solution...thatmaybe a mistake. As a hobbiest, I highly rely on my synoptic skill at this time of year. With that said, I will only give this a one and three shot at developing at thistime. In three days, I'll look at the vapor images, look at the overall structure of what may/maynot exist, and look at what is coming down the pike as far as trough development over the CONUS and MX. Based on that, the odds may go up or down.

I hope everyone is having a safe and enjoyable Memorial Day, please don't forget to take a moment to reflect on our guys and gals who are serving and have served our county to protect the freedoms and liberties we enjoy on a day to day basis. I'm deeply greatful to all generations that have served our county. If this includes you, I honor you and I deeply thank you.


scottsvb
(Weather Master)
Mon May 28 2007 10:40 PM
Re: Memorial Day Weekend Area to Watch

Models picking up on a system..possibly tropical in the SE gulf of Mexico by Fri-Sat....

Well its still not clear but the models are slowly converging on something now. The GFS now shows a 1005mb low crossing SW florida on Saturday. Along with the Nogaps.... this is also alined with the ECMWF. CMC and UKMet have it more N towards the Panhandle. Even the GFDL is picking up on a 1004-1006mb low Friday night nearing SW florida. (check the 18z EPAC system).

All in all its not clear..0z runs will tell some more..and consistancy till the low develops will give us a idea if its organized or if anything develops at all. In 24hrs or so..we will have a better idea.

Low is currently near 14.6N and 78.5W and moving WNW towards the Nic-Hond boarder by later Tuesday.. then as a upper trough-cutoff low develop over the N GOM on Weds-Sat moisture will feed into the system from the EPAC and pull anything down there N towards the SE GOM by Friday.


madmumbler
(Storm Tracker)
Tue May 29 2007 08:10 AM
Re: Memorial Day Weekend Area to Watch

Jim Syoen on channel 2 from Ft. Myers (today's his last day! *sob! cry!*) was talking about it this morning too. And he's never been a wave-mongerer type of weatherman. He said to watch the area towards the end of the week because models are starting to mention this.

We are DESPERATE for a nice wet tropical depression or low level TS to just SIT right over us. We're over 600 in drought numbers here in Charlotte.

Now, will the area over LA/TX drift east to the Panhandle?

And is the area the models are picking up on the stuff over the Yucatan peninsula right now?


Rich B
(British Meteorologist)
Tue May 29 2007 12:06 PM
Re: Memorial Day Weekend Area to Watch

Ok. Todays take on the SW Carib system so far...
It is still getting model support with a weak and quite broad system set to move across the Yucatan, or through the Yucatan Channel. Some models develop quite an intense system and take into the FL big bend (CMC) while others (UKMET) take a still weak system across the Big Bend but develop it off the GA / SC coast. GFDL takes a developing system just to the SE of the Keys and develops it off the east FL coast. General time frame for Florida impacts is late Friday. Now, a browse of the latest visible loops from GHCC show that there is a circulation - albeit small and relatively ill defined - centred about 15'N, 80'W, moving west or just north of due west. Convective activity has been almost non-existant, but has now begun to develop and increase just to the NE of the circulation. Could this be the start of what the models have been suggesting? Maybe, or maybe not


cchsweatherman
(Weather Watcher)
Tue May 29 2007 01:33 PM
Re: Memorial Day Weekend Area to Watch

First time posting on this site. I have been fascinated by the wealth of knowledge I have gained reading your comments.

Anyways, back to the Caribbean. Throughout the day, I have noticed some increased convention developing to the north of what appears to be some type of circulation. Living in South Florida, this is great news to see this moisture and convection likely being drawn up north. Lake Okeechobee will reportedly hit an all-time low today or tomorrow. Some amazing stuff.

Just hoping this models are right and we do have a developing system taking aim on drought and fire ravaged Florida.

(off-topic material removed - a reminder that this is not a Chat Room site)


Hurricane29
(Weather Guru)
Tue May 29 2007 01:35 PM
Re: Memorial Day Weekend Area to Watch

Dont see much down there just scattered convection in different areas.The model hype continues but no real true signs of development takeing shape as of yet.

MissBecky
(Weather Guru)
Tue May 29 2007 01:59 PM
Re: Memorial Day Weekend Area to Watch

The local mets in Tampa are taking note of a possible system by the weekend. As so many of us have noted, the GFS is unduly aggressive with this system, and it seems like they are discounting it, or at least not putting as much emphasis on that particular model.

My question though is with temps in the Gulf being what they are, why would this system be considered cold core?

SFC TROF OF LOW PRESSURE SLIGHTLY AND SLOWLY
DEVELOPS IN SOUTHERN GULF TO YUCATAN PEN AND GETS PUSHED ENEWARD
WITH UPPER SUPPORT OVER THE FL PENINSULA...THIS SYSTEM WOULD BE COLD
CORE NON TROPICAL TYPE SYSTEM. SHOULD SEE OVERRUNNING RAIN SHIELD
APPROACH THE AREA LATE FRI AHEAD OF AREA OF LOW PRESSURE WITH BULK
OF THE MOISTURE OVER THE AREA THRU THE DAY SAT. GFS APPEARS TO HAVE
ITS USUAL CONVECTIVE FEEDBACK WITH THESE GULF LOW/COLD FRONT
SYSTEMS...SO ITS RAINFALL TOTALS WHILE MUCH NEEDED LOOK OVERDONE.

PRECIP COVERAGE LOCATION CONCERNS...CANADIAN MODEL FURTHEST N WITH
MOST PRECIP OVER N FL WHILE ECMWF/NOGAPS FURTHEST S ONLY OVER S FL
PENINSULA WHILE THE GFS AND DGEX BRING RAIN SHIELD FROM THE CENTRAL
FL PENINSULA TO THE FL STRAITS.


danielwAdministrator
(Moderator)
Tue May 29 2007 09:47 PM
Afternoon Model Updates-NWS Melbourne,FL

Excerpt from the Afternoon AFD from NWS Melbourne,FL. A bit long for a post but very informative.

VIRTUALLY EVERY AVBL MODEL(NAM/GFS/UKM/ECM/CMC/NGP) AND EVEN SOME
OF LESSER KNOWN ONES (JMA/KMA-GDAPS) SHOW A DISCRETE LOW PRES SYSTEM GRADUALLY SPINNING UP ACROSS THE NW CARIBBEAN OVER THE NEXT 2-3 DAYS... THEN TURNING N/NEWD AND MOVING ACROSS FL OR VERY NEARLY SO...WITH THE SAT DAYTIME PD...GIVE OR TAKE A BIT...BEING THE BROAD CONSENSUS ON TIME FRAME FOR POTENTIAL EFFECTS ON SENSIBLE WX.
HOWEVER...EVEN WITH THIS LOOSE CONSENSUS...AND THE FACT THAT THIS IS NOW GETTING INTO THE DAY 3 TO 4 FCST TIME FRAME...CAVEATS STILL ABOUND.

NOTWITHSTANDING THE PREVIOUS MODEL "FALSE ALARMS"...THERE REMAIN SIGNIFICANT DIFFS BETWEEN THE MODELS - ENOUGH SO TO REMAIN WARY OF COMPLETELY BUYING INTO A HIGH POP/QPF EVENT FOR AT LEAST PART OF THE
CWA. FOR INSTANCE...SOME OF THE GUIDANCE (ECM/NGP/GFS) STILL KEEP THE SYSTEM FAR ENOUGH SOUTH/EAST SUCH THAT MUCH OF THE PRECIP MISSES ECFL...ALBEIT NOT BY MUCH. OTHERS (UKM/CMC/JMA...WITH THE H84 NAM
HINTING AS SUCH) BRING THE LOW FAR ENOUGH NORTH ACROSS THE ERN GOMEX TO GIVE THE CTRL PENINSULA HIGH POPS/DECENT QPF.

http://www.srh.noaa.gov/productview.php?pil=AFDMLB&version=1&max=61

(QPF is roughly the quantitative precipitation forecast... the amount of rain that will fall over X amount of time)


danielwAdministrator
(Moderator)
Wed May 30 2007 04:24 AM
New Area to Watch ???

As of 0800Z , 4 AM EDT, this morning. A medium sized MCS has moved offshore of Cancun and Cozumel,MX.

Short life span on the satellite loops is indicating a small convective tower in or near the center. And it appears to be making an attempt at establishing inflow on the Eastern side. Based on IR imagery.

Surface circulation appears to be just off the Middle to NW tip of the Yucatan Peninsula. Again with a short loop duration it's slightly hard to see a circular pattern in the images.

http://wwwghcc.msfc.nasa.gov/GOES/

http://wwwghcc.msfc.nasa.gov/GOES/goeseastconusir.html


cieldumort
(Moderator)
Wed May 30 2007 05:12 AM
Re: New Area to Watch ???

Been watching. Wish to add to what Daniel just said, that while it is still dark one might have an easier time making out the llc which does appear to be present off the tip of the Yucatan using the Night IR , and zooming in on the feature.

It is worth noting that this is not the area favored by the models which were brewing something a bit further south of here and then moving it up either across or very near Florida. It is also worth keeping in mind that shear is still quite high in this region, although it has been trending down over the past day or so. (CIMSS Shear Analysis)

Also possibly complicating things for any would-be tropical cyclones, TD2E is rather close to this part of the Caribbean and GOM, as is another surface low which seems to have formed to 2E's southeast, inland near El Salvador. Not only does this leave three areas of low pressure competing for fuel sources and dominance in the region, but killer outflows can blow out of the associated thunderstorms, and snuff out any incipient disturbance.

Having qualified with all of that, shears have been coming down some while things have kept bubbling for several days now.


Hootowl
(Weather Hobbyist)
Wed May 30 2007 07:17 AM
Re: Memorial Day Weekend Area to Watch

Thanks for that link!

Just a snippet from our local NWS disco this morning....

...DEEP TROPICAL MOISTURE WILL BE
PULLED NORTH ACROSS THE REGION FRIDAY NIGHT AND SATURDAY. THIS WILL
BE A DRAMATIC CHANGE TO THE DRY AIR THAT HAS PERSISTED FOR MUCH OF
THE LATTER PART OF MAY...AND SUMMERLIKE HUMIDITY WILL BE FELT AS
WINDS SHIFT SOUTHWEST OFF THE GULF OF MEXICO LATE SATURDAY.
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT...AND
NUMEROUS SHOWERS AND THUNDERSTORMS LIKELY SATURDAY AS DEEP TROPICAL
MOISTURE WILL HAVE ADVECTED OVER THE FLORIDA PENINSULA. POSSIBILITY
FOR SIGNIFICANT RAIN EVENT SINCE WEST CENTRAL AND SOUTHWEST FLORIDA
WOULD BE ON THE EAST SIDE OF THE STORM SYSTEM. BUT AGAIN...MUCH
UNCERTAINTY REMAINS...WOULD EXPECT SYSTEM TO BE EXITING THE AREA
SUNDAY WITH WEST TO SOUTHWEST FLOW CONTINUING TO ADVECT WARM MUGGY
AIR OFF THE GULF OF MEXICO.

http://www.srh.noaa.gov/productview.php?pil=TBWAFDTBW&version=0

Sure hope they are right and we get the much needed rain. They are currently showing a 70% chance for us on Saturday. Can't say I care much for the wording "storm system" though.


flarrfan
(Verified CFHC User)
Wed May 30 2007 08:59 AM
Re: New Area to Watch ???

I looked at the IR link when I woke up this morning and saw a well-formed area of convection that even appeared to have developed a COC during the night. Now four hours later I check the link again and see a big difference...seems to me this area is being sheared dramatically, and if this continues the significant rain event we need and were hoping for in west central Florida this weekend may be more of a non-event. Am I seeing this apparent shear correctly, and if so, any thoughts on what it means to drought relief here this weekend?

allan
(Weather Master)
Wed May 30 2007 09:18 AM
Re: New Area to Watch ???

Morning everyone,
nice blowup on the ULL this morning again.. though this time, it could stick for a while as the storm that models are forcasting is now starting to develop. CMC does an Alberto type system and head it just north of tampa as a strong TS or cat. 1 Hurricane according to the pressures. UKMET has a weak/moderate storm crossing central Florida then becomes a strong TS moving up the east coast. GFS finally recongizes storm development instead of just moisture and has it in the Gulf pointing towards Florida. NOGAPS has a fairly weak system 35-40 mph hitting right around where Charley hit and then strengthens it to a stronger storm going up the east coast.
.. Anyways.. looking at the model runs, there are about 3 scenarios in my case.
1. Storm developes rapidly into a strong TS and hits Florida hrd with heavy rain with winds from 50-65 mph.
2. Storm developes slowly and hits Florida with heavy rain yet winds are 35-45 mph., then becomes a stronger TS as it gets into the Gulf Stream with winds increasing to 50-60 mph.
3. The storm develops but as a non-tropical system and Florida just gets alot of rain with some gusty winds.
.. So which scenario do you think will play out?


Hurricane29
(Weather Guru)
Wed May 30 2007 09:23 AM
Re: New Area to Watch ???

This is what accuweather has to say about the developing low....I agree with there outlook.



AccuWeather.com is forecasting an active tropical season, and although Friday is only the first official day of the 2007 Atlantic Hurricane Season, we might already have something to watch. A tropical low will be developing over the northwest Caribbean over the next two days, and upper-level winds will help to pull this storm northward. While it is unlikely that this will become a strong tropical system, it will have to be monitored for development. There is a good chance that much of the Florida peninsula will receive significant rainfall from this system, and there are indications that it may reach northward into Georgia and the Carolinas. After several months of abnormally dry weather, any rainfall is welcome, and a big rainmaker like this would be a blessing.


cchsweatherman
(Weather Watcher)
Wed May 30 2007 09:48 AM
Re: New Area to Watch ???

I took a look at the latest forecast models and the CMC seems to indicate a TS or Cat 1 hurricane for Florida this weekend. Very interesting! Either way, Florida will finally recieved a gift from God in the form of a tropical soaker over the weekend.

B.T.W. Has anyone noticed the rain over the Sahara over the past few weeks and Moscow reaching highs in the 90's for six consecutive days? Remarkable developments! Does this mean there will be less Saharan dust?

(off-topic material was removed)


Hurricane29
(Weather Guru)
Wed May 30 2007 10:12 AM
Re: New Area to Watch ???

Piece of discussion from HPC earlier this morning...

WITH EVOLVING SFC LOW PRESSURE BY THE LATTER HALF OF THE PERIOD... PREFER LEANING TOWARD THE UKMET/12Z ECMWF/00Z NCEP-GEFS ENSEMBLE MEAN... OR LACKING THOSE OPTIONS... A WEAKER VERSION OF THE NAM.
TYPICALLY PREMATURE EVOLUTION OF SYSTEMS ORIGINATING FROM TROPICAL LATITUDES FAVORS DISCOUNTING THE CANADIAN GLBL WHICH BRINGS A WELL DEFINED SFC LOW INTO NERN FL BY EARLY SAT. THE GFS IS THE NEXT FASTEST MODEL WITH A TRACK MUCH FARTHER WSW OF THE CANADIAN GLBL.
THE NAM IS LIKELY TOO DEEP BASED ON ITS HISTORY OF LOWER LATITUDE SYSTEMS FROM LAST YEAR... THOUGH ITS SLOWER PROGRESSION AND INTERMEDIATE SFC LOW TRACK ARE GENERALLY SUPPORTED BY THE UKMET/12Z ECMWF. NAM EVOLUTION THAT CONSOLIDATES ENERGY FROM CNTRL AMERICA AND VICINITY AND GFS EVOLUTION USING ENERGY INITIALLY OVER/NEAR THE YUCATAN PENINSULA ARE BOTH LOW CONFIDENCE FCSTS... ESPECIALLY WITH THE LACK OF A CURRENT WELL DEFINED FEATURE OVER THE ORIGINATING REGION IN SATL IMAGERY AND APPEARANCE OF FEEDBACK IN THE MODEL QPF PATTERN. THE LARGE SCALE PATTERN
DOES FAVOR INCREASED FLOW OF MOISTURE AND SOME GRADUAL LOWERING OF SFC PRESSURES OVER THE SERN GULF/FL LATER IN THE PERIOD THOUGH. ABOVE CONSIDERATIONS MAKE THE UKMET/12Z ECMWF/00Z NCEP-GEFS
ENSEMBLE MEAN THE BEST OPTIONS AT THIS TIME.


NewWatcher
(Storm Tracker)
Wed May 30 2007 10:33 AM
Re: New Area to Watch ???

NHC Floater 2 is now on this area... being called Invest.
Convection is flaring quite nicely this a.m.
Something to Watch


hurricaneguy
(Weather Hobbyist)
Wed May 30 2007 10:52 AM
Re: New Area to Watch ???

I think could be our first "tropical" player of the sason. The CMC has a well defined storm off the coast of W Florida 72 hrs from now. I don't think this would be a very big storm though, if one forms at all. It may be a carbon copy of Alberto from last year. Just keeping an eye on this is all we can do for now.

cchsweatherman
(Weather Watcher)
Wed May 30 2007 11:12 AM
Re: New Area to Watch ???

The radar out of Florida is now picking up some of the "Invest". Looks like a big soaker is finally coming to South Florida. Intellicast Radar

madmumbler
(Storm Tracker)
Wed May 30 2007 01:07 PM
Re: New Area to Watch ???

I'm looking at the floater, where is the potential LLC? To me it looks like it's around 23N/87W -- is that right? Am I looking at that right?

*please oh please oh please bring rain!!*


scottsvb
(Weather Master)
Wed May 30 2007 01:29 PM
Re: New Area to Watch ???

nope..that is a mid level inpulse from the T-storm complex that went out over Yucitan Channel last night.

The center of circulation is forming around 16N and 86W just north of honduras...its weak elongated near 1010mb but pressures are falling and will continue.

Strength of this and movement is still up in the air. Models on the 12z runs are all over the place...The GFS has been flip-floping from the Central GOM to now leaving central and northern florida dry and only S Florida receiving rains. I feel as of right now..this is a outliner....but lets see what the 0z runs tonight show.


Hurricane29
(Weather Guru)
Wed May 30 2007 01:35 PM
Re: New Area to Watch ???

I doupt anything more significant then some good tropical moisture for florida will come out of this as shear values presently are running at 30-50kts of windshear across the gulf.Unfortunately much more rain will be needed in the lake before things begin to improve.

scottsvb
(Weather Master)
Wed May 30 2007 01:51 PM
Re: New Area to Watch ???

Probably right... question everyone wants to know is strength of the low and where it goes...if it remains weak and does what the 12Z gfs says...then central and N florida will get no relief for the drought and fires.

Ron Basso
(Storm Tracker)
Wed May 30 2007 01:59 PM
Re: Memorial Day Weekend Area to Watch

The latest 12Z CMC model really blows up the low pressure in the western carribean. Looks like it takes it to a CAT 1 Hurricane prior to landfall in the Big Bend region of FL. The 12Z UKMET is considerably weaker while bringing a broad low across north-central FL. 12Z NAM indicates a slower motion toward the Big Bend at tropical storm strength (1004 mb). Looks like the system will be a hybrid (sub-tropical) with most of the wind and weather on the east side.

http://moe.met.fsu.edu/cgi-bin/cmctc2.cg...;hour=Animation

http://moe.met.fsu.edu/cgi-bin/ukmtc2.cg...;hour=Animation

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/


madmumbler
(Storm Tracker)
Wed May 30 2007 02:11 PM
Re: New Area to Watch ???

Quote:

nope..that is a mid level inpulse from the T-storm complex that went out over Yucitan Channel last night.

The center of circulation is forming around 16N and 86W just north of honduras...its weak elongated near 1010mb but pressures are falling and will continue.





Okay, I see where you're pointing that out. But that looks like it's trying to spin clockwise. Or am I looking at that wrong? Does that mean it has less of a chance of developing?


Ron Basso
(Storm Tracker)
Wed May 30 2007 02:12 PM
Re: Memorial Day Weekend Area to Watch

Looks like a broad surface low exists near 17N-86W , just off the north coast of Honduras. The models indicate that this low will slowly drift north to the north coast of the Yucatan in 36-48 hrs.

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


scottsvb
(Weather Master)
Wed May 30 2007 02:15 PM
Re: New Area to Watch ???

I see no clockwise circulation...probably the high clouds you see.

Anyways center is weak and elongated around 16.5N and 86W.... on a side note there is a weak low in the BOC but I expect that to weaken as the caribbean system takes shape. Still alot of questions with this system.


Hurricane29
(Weather Guru)
Wed May 30 2007 02:17 PM
Re: Memorial Day Weekend Area to Watch

Quote:

Looks like a broad surface low exists near 17N-86W , just off the north coast of Honduras. The models indicate that this low will slowly drift north to the north coast of the Yucatan in 36-48 hrs.

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




If it moves into the gulf it will run into unfavorable upper level winds meaning 30-50kt windshear.

Steering winds will most likely keep this a southeast event.


scottsvb
(Weather Master)
Wed May 30 2007 02:29 PM
Re: Memorial Day Weekend Area to Watch

Actually 29 with the system moving intangent with the upperlevel winds...shear wont be too bad...also there is more ridging S-N. Overall there will be some shear.

Hurricane29
(Weather Guru)
Wed May 30 2007 03:19 PM
Re: Memorial Day Weekend Area to Watch

"Thursday night-Sat...significant change in the pattern is expected as the
ridge in the western Atlantic breaks down Thursday night-Fri.
Meanwhile...broad cyclonic flow in the western Gulf will draw
tropical moisture northward towards the state...ultimately resulting
in increasing rain changes late this week and early this weekend.
NAM-WRF suggests an area of low pressure north of the Yucatan will
lift northward through the Gulf...which would produce beneficial
rainfall across the forecast area. However...recent trends in the
GFS indicate that a track further to the south and east is more
likely. This would keep the deep tropical moisture to our
south...with only scattered shower activity Friday and Sat as a wave of
low pressure tracks across the southern peninsula. It would not be
fair to totally rule out a wetter solution at this point as depicted
by HPC and the European model (ecmwf)...which takes the low across The Big Bend and
northeastward up the southeast coast. Given the anomalous nature of
the pattern along with the fact that the event is still a few days
out...plan at this point is to only nudge probability of precipitation up slightly from
previous forecast."...........

(I'll repeat this request one more time: If you quote an official source, please STATE THE SOURCE in your post. In this case I believe its the NWS MLB Forecast Discussion bulletin.)


Ron Basso
(Storm Tracker)
Wed May 30 2007 03:30 PM
Re: Memorial Day Weekend Area to Watch

Latest 12Z Euro takes a moderate tropical storm into the Big Bend region of FL on Sunday morning. If this pans out, the entire peninsula should see some extremely beneficial rains and possibly tropical storm force winds at least over the west side of the peninsula.

http://www.ecmwf.int/products/forecasts/...s!2007053012!!/


doug
(Weather Analyst)
Wed May 30 2007 04:47 PM
Re: Memorial Day Weekend Area to Watch

The NHC's TWD issued at 2:05 p.m. today seems to buy the GFS representation of the system remaing a surface trough which will pull out generally to the NE...
We just need that to at least drift far enough north to get rain into the peninsula...
They represented that the amplitudes were off the surface and several cyclonic non surface rotations were apparent south of 25N and along 87W.
EDS


allan
(Weather Master)
Wed May 30 2007 04:55 PM
Re: Memorial Day Weekend Area to Watch

I see a good but dis-organized circulation next to the Yucatan on the bottom of all that moisture. I also see banding features starting up on the fringes of the storm. Surprised myself that it's not mentioned on NRL yet. Probabaly gonna tag it if it persists or gets better organized through the evening. I'm gonna see what my local news says about it in a few minutes and i'll let you know what good old Tom Sorrels says. I think Barry is going to be on the way in a few days. When I saw the CMC, my jaw literally dropped LOL.

Bloodstar
(Moderator)
Wed May 30 2007 05:18 PM
Re: Memorial Day Weekend Area to Watch

Quote:

I see a good but dis-organized circulation next to the Yucatan on the bottom of all that moisture. I also see banding features starting up on the fringes of the storm. Surprised myself that it's not mentioned on NRL yet. Probabaly gonna tag it if it persists or gets better organized through the evening. I'm gonna see what my local news says about it in a few minutes and i'll let you know what good old Tom Sorrels says. I think Barry is going to be on the way in a few days. When I saw the CMC, my jaw literally dropped LOL.




Nothing on the surface at this point.

If LLC is going to form, it will need to pop up somewhere where it can take advantage of the upper level winds and use it as an outflow channel, rather than be torn apart by same said winds.

The current best place for a LLC to form is around 20N 85W. Should something spin up there, the system might have time to do something interesting.

As it is, the models are currently over reacting, and until things start to spin up, there's no need to hope/worry.

Florida and south Georgia needs the rain, so keep your fingers crossed something gets some moisture and rain up there and not more wind. which would be really bad.


typhoon_tip
(Meteorologist)
Wed May 30 2007 05:51 PM
Re: Memorial Day Weekend Area to Watch



The consensus is that if something does evolve in the vicinity of the NW Caribbean and eastern Gulf it would be subtropical and nature. Looking at the regional synoptics this afternoon and balancing those observations against the majority Global model outlooks I would have to agree, and assert that hybrid is unavoidable unless certain parameters change.

Currently there is clearly a trough defined by cyclone large scale motion from off Old Mexico/TX, curving toward the NE over the Gulf. Winds in the mid and upper levels in this band of westerlies are humming along at some 40kts, and even 50kts in some soundings.

The Global models show only increasing tendencies for troughing in the region over the next few days, as the entire domain of N/A goes through a period of amplification. Later on...after Day 5 or perhaps 6, that period of amplification may very well wane into more zonal character, as the larger scale hemispheric teleconnectors are also suggesting (Elevating NAO/AO contracting the westerlies more polarward). But, our system of interest, whatever becomes of it, will be by the boards.

With this kind of synoptic evolution in the deep layer winds, this will be a shear system. The heavier QPF will be NE of whatever center defines. The best hope for this to develop further, given the described regime, is for it to smartly begin moving along with the flow, such that storm relative shear reduces the impact of the westerlies. Because there will be a trough, any cyclonic development will entrain backside drier continental air and probably some deeper layer dynamics more akin to baroclinic storm development, so there is less likelihood of this being of purer tropical form if it ever gets going.

As a side note: Nevertheless...we are greatful for whatever water is received in southern Florida. Lake Okee. has set a record this day for the lowest ever recorded lake level. Normal is 13 feet. It is now under 9! This is a big, big problem for the 10 million citizens that depend on it for their fresh water source. Let along the damage to the surrounding Everglades habitat.


Hurricane29
(Weather Guru)
Wed May 30 2007 06:32 PM
Re: Memorial Day Weekend Area to Watch

Seems like the floater has been moved to the sw towards the covection to the south of cuba.

http://www.ssd.noaa.gov/goes/flt/t2/vis.jpg


Ron Basso
(Storm Tracker)
Wed May 30 2007 07:25 PM
Re: Memorial Day Weekend Area to Watch

Pressure dropping at buoy 42056 with east winds 20-25 kts. Pressure also falling at buoy 42057 - now at 29.81 in.

http://www.ndbc.noaa.gov/show_plot.php?station=42056&meas=wdpr&uom=E


Ron Basso
(Storm Tracker)
Wed May 30 2007 07:33 PM
Re: Memorial Day Weekend Area to Watch

Broad area of low pressure w/o much convection evident near 17N-86W. Shear looks a little high but it is forecast to relax in this area east of Belieze and north of Honduras. Look for convection to increase in this location over the next 24 hours for possible tropical cyclone development.

http://hadar.cira.colostate.edu/ramsdis/online/trop_ge_vis_float1_0.html


Ed DunhamAdministrator
(Former Meteorologist & CFHC Forum Moderator (Ed Passed Away on May 14, 2017))
Wed May 30 2007 07:43 PM
A Couple of Notes

From the description for the 2007 News Talkback:
"you can only reply to the topics covered in existing main page articles."

Please place any comments on the Florida drought in the existing thread in the Other Weather Events forum rather than this Main Page thread.

When placing a quote from an official source in your post, please include the source of the material.
ED


allan
(Weather Master)
Wed May 30 2007 08:28 PM
Re: A Couple of Notes

Well it looks very disorganized now.. evening weakenings could lead to morning strengthening. So it's deffinatly a wait and see situation. Maybe a blow up tonight, then again maybe not. I hear shear is expected to relax tommorrow to allow some organization in this area of disturbed weather. Kind of figured I see this tonight and now i'm figuring i'll see a nice blow up tommorrow morning.. can't wait for the 00z runs later tonight... bound to see what the CMC has in store LOL

HanKFranK
(User)
Wed May 30 2007 10:23 PM
incipient system?

looks like the tropics don't want to take the rest of may off..
some kind of low pressure area--maybe a sheared/lopsided tropical cyclone or maybe one of those not quite closed trough lows--is getting busy developing in the nw caribbean near the coast of belize tonight. most of the globals are showing its continued evolution and perhaps a baroclinic deepening run as it moves nne towards florida. whether a system forms or not florida is in for one of those significant tropical rain events.
it's hard to say how things will play out with how complicated things are on the eastpac side. barbara got its act together over the last couple of days and is a small system embedded in one of those monsoon trough environments that extends eastward from weakening alvin, to central america and across to the synoptically favorable environment east of the digging upper trough over the western caribbean. interestingly another small vorticity max system is hanging near the coast of el salvador, perhaps stealing a bit of barbara's fire. barbara is not dominating and controlling the larger-scale atmospheric motions in the monsoon trough, so it is not strengthening quickly, but it appears that it will eventually get organized as well, and threaten mexico. barbara taking its time is probably important for preserving the environment that may allow an atlantic system to organize and threaten florida, as a strong system with an impressive outflow would likely undo the positive but challenging upper air conditions to the east.
this is sort of remarkable, that here at the end of may we are seeing another potential tropical development on the atlantic side, which may end up being a cross-basin triplet with the pacific systems induced by either an mjo burst or one of those easterly surges in the tropical pacific. keep an eye to the northwest caribbean for the next two days as something may quickly spring up, in the manner that arlene did in early june 2005.
may have to go to another thread tomorrow.
HF 0322z31may


allan
(Weather Master)
Wed May 30 2007 10:38 PM
Re: incipient system?

Hmm.. something interesting is trying to organize south of this whole mess.. southeast of the Yucatan, in very warm waters and favorable conditions, a bit of banding going on there.. could this be the "actual" system?
Check out the western atlantic satellite.. and examine closely the south part of what I call a mess!
I knew something interesting was gonna come into play sometime tonight.. and this area is basically where the models start this "possible" hybrid/tropical system. I'd watch that area, it's deffinatly of interest.. better then what we had and have been tracking today. The NHC put an invest floater on the blow up from the ULL.. but I think they should move it south of that.


Hurricane29
(Weather Guru)
Wed May 30 2007 10:58 PM
Re: incipient system?

Quote:

Hmm.. something interesting is trying to organize south of this whole mess.. southeast of the Yucatan, in very warm waters and favorable conditions, a bit of banding going on there.. could this be the "actual" system?
Check out the western atlantic satellite.. and examine closely the south part of what I call a mess!
I knew something interesting was gonna come into play sometime tonight.. and this area is basically where the models start this "possible" hybrid/tropical system. I'd watch that area, it's deffinatly of interest.. better then what we had and have been tracking today. The NHC put an invest floater on the blow up from the ULL.. but I think they should move it south of that.




Yea allan the thunderstorm activity has been rather persistent tonight,lets see what takes palce over night.


Clark
(Meteorologist)
Thu May 31 2007 12:26 AM
Re: Memorial Day Weekend Area to Watch

I don't have a lot to add to what Tip and HF outlined in the past 10 posts or so, so I'll keep this brief. The way the upper level pattern has established itself, anything that develops is likely headed for the Florida panhandle. The trough over the Gulf isn't going anywhere; water vapor loops tonight clearly show it digging in over Mexico and the western Gulf and the system well to its north over the N. Plains isn't going anywhere anytime soon. Basically, what you see is what you get right now unless the pattern unexpectedly changes. Don't bank on it.

Second question is of what degree of development we are going to see. Generally, the sooner it develops, the more likely it gets a tropical classification. Though conditions are not overly favorable there in the NW Caribbean, shear is slightly weaker and upper level diffluence (winds moving apart directionally) is favorable for at least persistent convective development. It does have the Yucatan Peninsula to contend with, however, hindering those prospects in the short-term. The longer it waits to develop, the stronger the baroclinic (midlatitude) forcing it will encounter and thus the more likely it is of the subtropical or extratropical variety.

Tip made a good comment about the improved prospects if/as the storm starts to accelerate to the northeast; this would reduce the storm-relative shear across it and allow for some added development. We have seen a number of Gulf storms get going over the past 10 years under such conditions, with all of them ending up lopsided to the east and not particularly strong overall.

So, if we assume something gets going, what can we expect? Mostly rain. There likely won't be the long fetch or duration (or intensity) of winds to lead to significant surge -- whether tropical or extratropical. Storm intensity should be kept in check due to shear and cool SSTs generally in the mid-upper 70s over a shallow layer in the northern half of the Gulf. If it evolves baroclinically/extratropically, there's just not enough energy aloft over the Gulf to see it significantly deepen in that manner either. Think moderate tropical storm on the high end. It does have plenty of moisture to work with, though, and should spread all of it over Florida and the coastal SE into the coming weekend. As a result, a widespread moderate rain event is possible if not likely; generally 1-2" with spots at 3-6" depending on the track and structural evolution.

All of that said -- a hybrid cyclone heading for Florida into the weekend looks like a good bet, likely with some much needed rains for most if not all of the state. Will it be our second classified storm of the year? Jury is still out; I would tend to say no. One to watch, though.


Bloodstar
(Moderator)
Thu May 31 2007 02:35 AM
Re: Memorial Day Weekend Area to Watch

Still no sign of a closed surface low at the moment, and pressures still haven't shown much drop, but the convection is certainly impressive over the area of 80W 19N. Tomorrow afternoon/evening will be the most likely time for something to start pulling together at the surface. if it hasn't started cranking up by then, we probably won't see anything tropical with this. Hybrid, perhaps. but not a pure tropical system.

Pressures are still around 1010MB, what will they be in the afternoon?

- Mark (yeah, I should be asleep)


cieldumort
(Moderator)
Thu May 31 2007 03:28 AM
Re: Memorial Day Weekend Area to Watch

Again, please forgive the late additions (we keep having very active wx here in Texas)

Everybody, I was a holdout through much of the day, especially looking at such unfavorable shear atop already marginal SSTs in much of the GOM. Best I could argue for was a highly "lopsided TC" (which of course just about never gets a name, baring extenuating reasons).. and I still argue that the most likely scenario is for some kind of hybrid that is or is not name-worthy... But gee whiz, I concede to what is going on tonight. Here are two examples

Surface pressures and winds in the region

Funktop loop centered over Invest... just wow

What can I say, I am impressed!


GuppieGrouper
(Weather Master)
Thu May 31 2007 05:41 AM
Re: Memorial Day Weekend Area to Watch

The 5am sat loop indicates the general direction of the deep moisture and red top clouds will be pulled over Cuba. The apparent counter clock wise motion of dry air to the east of the convection seems to be vaccuuming up the storm this morning. I suppose that this could change over time, but so far everything has a fluid movement East. I am not expecting a great deal of rain from this Caribbean system unless the moisture deepens over Central Florida. Our Lakeland Monster is still in charge of the drought,.

allan
(Weather Master)
Thu May 31 2007 07:41 AM
Re: Memorial Day Weekend Area to Watch

Good morning!
I was expecting something like this to happen but really now surprised that this is not yet tagged. I thik once the visible satellite comes in, they will be able to determine where the circulation center is and probably tag it by later this morning. I'm impressed, and by reading some of the wunderground bloggers, they say it's headed south of Florida?? LOL
Anyways... very nice blow up of storms, now this is where we start to get busy!


HURRICANELONNY
(Weather Guru)
Thu May 31 2007 07:43 AM
Re: Memorial Day Weekend Area to Watch

I hate to say it but you might be right. Most of the High tops are being blown east. If the GFS verifies. Which usually doesn't then the low would head near S Fl. with most of the moisture out to sea. It's still a little early to know where the main moisture will go. The shear in the Gulf is pretty high so I doubt we will get too much in development. Maybe a hybrid system.

cchsweatherman
(Weather Watcher)
Thu May 31 2007 08:58 AM
Re: Memorial Day Weekend Area to Watch

Have you guys noticed how all the storms seem to banding around a COC? Taking a look at the latest IR image, it appears as if the storms are now forming bands which would be an obvious sign that there is some COC out there.

BREAKING NEWS: The Navy Website has now designated this as Invest 92L. We now have a true investigation area. Waiting on report from NHC.


Hurricane29
(Weather Guru)
Thu May 31 2007 09:32 AM
Re: Memorial Day Weekend Area to Watch

Our 3rd invest in may....Winds are at 25kts.




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