ATL: Tropical Depression Fay

[BigA]

94L all over again.This thing will fight to hold on untill it gets past DR and then BOOM

I feel ignorant, but what became of 94L? If it was an infamous storm, I am not trying to joke or be dramatic. I mean this as a sincere question.

[Cyclone1]

94L all over again.This thing will fight to hold on untill it gets past DR and then BOOM

I feel ignorant, but what became of 94L? If it was an infamous storm, I am not trying to joke or be dramatic. I mean this as a sincere question.

Dolly.

[gatorcane]

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Well the Upper-level trough and TUTT has done a good job on this invest as should be expected. Recall the forecast reasoning: 92L would struggle under the TUTT for several days until it gets underneath the building Bermuda High ridge. Looks like in about 24 hours the environment becomes much more favorable for 92L. At that point a fairly nice West bend commences and it takes off. I still see nothing that goes against my initial forecast reasoning at this time which showed 92L skirting or just missing the Leewards to the NE and not developing until its about north of Puerto Rico or so. I expect development into a hurricane approaching the Bahamas and possibily threatening Southern Florida. Looks like the GFSx is backing off on some ridging at the 5 day mark at this time which could allow a WNW to NW bend towards the end of the 5-7 day forecast period (hence the reason to extend mainland southern florida as a possible target area). Anywhere from Northern Cuba up through Southern Florida and the Bahamas should closely monitor the progress of this invest at this time.

[Vortex]

I think it is extremely prudent to not "write it off." As previously mentioned, the wave axis has entered the shear zone (strongest UL winds) from the upper low to the north. In other words, the fact that the thunderstorms are sheared via strong divergence should have been anticipated. The system is currently encountering the worst conditions, which will continue during the next ~24-28 hours. Shear will likely decrease after this time frame, as the system enters the west side of the shear zone and an upper level anticyclone builds at 300 mb. There are also several reasons for concerns down the line in the Bahamas and southern Florida. This system will survive the hostile conditions over the next 24 hours.

1. LL 850 mb vorticity has been quite strong near the northern end of the wave axis (http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8sht.html). This would eventually favor the formation of a surface low in the region of best LL convergence and ascent. The bolded portion is important: with an increasingly unstable boundary layer, thunderstorms would develop and result in the development of a LLC. Note that the ascent provided by the UL divergence (shear) is partially contributing to convection developing in the vicinity of the strongest 850 mb vorticity. The fact that the vorticity has been persistent is disconcerting, and it will certainly remain as the system moves WNW across the NE Caribbean toward the islands of the Bahamas.

2. The wave axis is still present. In other words, even if most of the thunderstorms dissipate, the wave axis will still remain as it moves WNW across the NE Caribbean toward the Bahamas. The associated LL convergence line will be present, so additional thunderstorms can develop down the line, depending on other synoptic/thermodynamic factors as well. TCs can eventually develop if the wave axis/convergence line eventually enters more conducive conditions.

3. Most of the models (depicting a TC) have remained consistent: they do NOT develop the TC until the system is NW of Puerto Rico. This would coincide with the more conducive upper air regime. Additionally, WV data indicates the TUTT to the west is continuing to progress westward. As the upper low north of 92L moves slowly NE and the system (92L) passes the shear zone beyond ~24-28 hours, we will observe the gradual evolution of the aforementioned 300 mb anticyclone.

Miami,

As usualy excellent analysis.

[GeneratorPower]

One thing is for sure. If this thing had formed earlier and become a named system it would have started stealing news coverage and people would have started the freak-out process already. Problem is, the closer in it develops the less time people have to panic and get ready. This will not be made any better by people being absorbed in the Olympics.

Should it develop, you could have a mess on your hands in South Florida. At least any Gulf threat looks to give a bit more warning.

[GeneratorPower]

Look at the visible loop below. First thing I noticed was the low cloud swirls spinning nicely around a central point under the convection. Hmnnnn......!

http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

[Stormcenter]

The NWS out of Miami, FL does not seem
too concerned at all about 92L. Below is
an excerpt from this morning's discussion.

For Friday and Saturday...the 00z run of the GFS has again
continued the delay of returning the subtropical ridge northward
across the region...and instead lags the tail end of the eastern
Continental U.S. Trough as well as a weak surface trough across South Florida. This
would bring more moisture and higher probability of precipitation across the region. A quick glance at the 00z European model (ecmwf) is in general agreement...but will not change the forecast much as this is a sharp change from previous
model runs.
Beyond Saturday...models try to develop some east flow on Sunday as some weak ridging becomes established north of the region...and then a tropical wave may approach the region from the east Monday and Tuesday with some increase in moisture.

[cycloneye]

Look at the visible loop below. First thing I noticed was the low cloud swirls spinning nicely around a central point under the convection. Hmnnnn......!

http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

And is moving due west not wnw.

[gatorcane]

Yes it seems to have taken on a more due W movement as of late. Lets see if that trend continues.

Convection is really starting to blossom also...lets see if it persists.

[Gustywind]

13/1145 UTC 15.9N 57.5W TOO WEAK 92L -- Atlantic Ocean
http://www.ssd.noaa.gov/PS/TROP/positions.html

[deltadog03]

Looking a bit better. The Tutts are slowly moving away from the invest. Lets see how long this convection lasts. Dosn't look horribly sheared right now...
http://www.ssd.noaa.gov/goes/east/tatl/loop-wv.html

[GeneratorPower]

The fact that a local NWS office doesn't say anything about it just means they aren't going to be the one to start getting people concerned. That's why they say "trough" and "surface trough" and use terms like "closed low" instead of "Cat 3 hurricane". The news stations can't cause a stir with a big, scarry "closed low".

[CourierPR]

One thing is for sure. If this thing had formed earlier and become a named system it would have started stealing news coverage and people would have started the freak-out process already. Problem is, the closer in it develops the less time people have to panic and get ready. This will not be made any better by people being absorbed in the Olympics.

Should it develop, you could have a mess on your hands in South Florida. At least any Gulf threat looks to give a bit more warning.

Those of us in the hurricane belt need to have our plans and supplies ready now. We procrastinate at our peril.

[GeneratorPower]

Right, CourierPR. Unfortunately, the masses don't prepare like they should and if the above situation took place, there would be a bigger-than-normal panic.

[Blown Away]

The NWS out of Miami, FL does not seem
too concerned at all about 92L. Below is
an excerpt from this morning's discussion.

For Friday and Saturday...the 00z run of the GFS has again
continued the delay of returning the subtropical ridge northward
across the region...and instead lags the tail end of the eastern
Continental U.S. Trough as well as a weak surface trough across South Florida. This would bring more moisture and higher probability of precipitation across the region. A quick glance at the 00z European model (ecmwf) is in general agreement...but will not change the forecast much as this is a sharp change from previous
model runs. Beyond Saturday...models try to develop some east flow on Sunday as some weak ridging becomes established north of the region...and then a tropical wave may approach the region from the east Monday and Tuesday with some increase in moisture.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
404 AM EDT WED AUG 13 2008

.DISCUSSION...

SAT-SUN...WESTERLY FLOW SATURDAY SHIFTS TO THE NORTH SUNDAY AND TO THE EAST BY MONDAY AS LOW CONTINUES LIFTING NORTHEAST AND HIGH PRESSURE OVER THE SOUTHEAST RIDGES DOWN THE PENINSULA.

MON-TUE...EASTERLY FLOW OVER THE SOUTHERN CWA STRENGTHENS MONDAY THEN AS A TROPICAL WAVE MOVING ACROSS THE CENTRAL AND SOUTHERN BAHAMA ISLANDS AND INTO THE FLORIDA STRAITS. FLOW DIMINISHES TUE AS TROUGH AXIS MOVES ACROSS FLORIDA. BETTER CHANCES FOR RAIN IN THE DEEPER MOISTURE OVER THE SOUTHERN THIRD OF CWA.

[Steve]

>>I think it is extremely prudent to not "write it off."

Great post as usual Miami. I appreciate the effort you and guys like Aric are putting into your analyses, which said posts are proving to be better than what other people are posting. Reminds me of HankFrank on CFHC who often had the best work even though he was still in school.

For those of you offering worthless posts last night - looking your way Mecklenberg, among others - can you let go of the ADHD stuff for a while? Nothing was likely going to happen with 92L, if ever, until late this week. It's a tropical wave that we've been watching since Sunday and wasn't likely to do anything for a while.
---------------------------
For everyone else, global models have been pretty close to one another even as their solutions have varied from run to run. 00z runs are looking like a threat to the Bahamas and SE Florida early next week. Looks like a turn to the north late in the runs. Also, none of the runs that were throwing high pressure (of Canadian origin) in there and subsequently giving 92L a push to the W or WNW are doing that anymore. Perhaps a weak, transient trough slides by to the north and gives 92L a tug or slows it down waiting for stronger steering currents. Gonna be an interesting few days for you folks down in the Keys and Miami.

Steve

[HURAKAN]

The blob now appears to be moving westward. Right?

[Gustywind]

Racing on Dominica and maybe Guadeloupe
We should experience some showers and scattered thunderstorms given the latest weather forecast given by our pro mets, but no more hopefully:D something good to erase the little drought andthe dry atmosphere on the island.
http://www.meteo.fr/temps/domtom/antill ... Tagant.jpg

[Sanibel]

Some times I feel like I am typing to myself. I said yesterday that 92L was a weird disappearer and that it already almost wiped out and that last night's drying up was just another deep d-min - and that 92 was an early morning d-maxer. Meanwhile some pro's were calling for dissipation.

Anyway, I think 92 has proven itself and should develop now.

[Stormcenter]

>>I think it is extremely prudent to not "write it off."

Great post as usual Miami. I appreciate the effort you and guys like Aric are putting into your analyses, which said posts are proving to be better than what other people are posting. Reminds me of HankFrank on CFHC who often had the best work even though he was still in school.

For those of you offering worthless posts last night - looking your way Mecklenberg, among others - can you let go of the ADHD stuff for a while? Nothing was likely going to happen with 92L, if ever, until late this week. It's a tropical wave that we've been watching since Sunday and wasn't likely to do anything for a while.
---------------------------
For everyone else, global models have been pretty close to one another even as their solutions have varied from run to run. 00z runs are looking like a threat to the Bahamas and SE Florida early next week. Looks like a turn to the north late in the runs. Also, none of the runs that were throwing high pressure (of Canadian origin) in there and subsequently giving 92L a push to the W or WNW are doing that anymore. Perhaps a weak, transient trough slides by to the north and gives 92L a tug or slows it down waiting for stronger steering currents. Gonna be an interesting few days for you folks down in the Keys and Miami.

Steve

I actually believe very few (on this board) including myself are writing off 92L. Look just think back to 2005 and that K storm. I'm NOT saying this will or can be anything like that but only how quickly these can spin up.