ATL: PALOMA - Tropical Depression - Discussion

[MGC]

Sure is a mess down in the Caribbean Sea this morning. Does look to be a new low center reforming. The old center south of the convection is gone. As long as the center can remain near the convection there is a chance of development.....MGC

[gatorcane]

When I look at this VIS loop of 93L I see it drifting WNW or W with a center about 14N and 82 W...

will it cross into Central America?

http://metofis.rsmas.miami.edu/~dortt/s ... 1_loop.gif

[Sanibel]

I see a weak center by 13.75-81.75.

It almost looks like a ULL formed over it.

Conditions probably aren't strong enough to burst it and pull it together.

[Ed Mahmoud]

Now that recon is scheduled for tomorrow, it has no chance of being upgraded before then short of completely covering the low level center with convection, clear banding, and ship reports of winds in excess of 50 knots. An eye feature wouldn't hurt either.


The center is mostly exposed, and somewhat elliptical looking. I think a reasonable person could make an argument that there have been numbered depressions that didn't look this good, but as slowly as it is organizing, it can wait until tomorrow afternoon to be named.

[jinftl]

Update from Dr. Jeff Masters this morning...

An area of disturbed weather (93L) a few hundred miles east of the Nicaraguan coast, is growing more organized, and has the potential to develop into a tropical storm this week. This morning's QuikSCAT pass revealed that the circulation center near 12N 81W is better defined and is more circular.

However, visible satellite images show that the heaviest thunderstorm activity is about 200 miles to the north of the center, and there is very little heavy thunderstorm activity near the center. It appears that the center of circulation is now attempting to relocate near the heaviest thunderstorms, somewhere near 14N 81W. This relocation will make last night's model runs a poor judge of how 93L might develop. The disturbance has been drifting west-northwest to northwest over the past 18 hours. Wind shear is a moderate 15 knots, and heavy thunderstorm activity has shown a moderate increase in intensity and areal coverage over the past few hours.


The forecast
Wind shear is expected to remain in the moderate range, 10-20 knots, over the southern Caribbean during the next three days. Water temperatures are warm, 29.5°C, and this warm water extends to great depth. These are favorable conditions for intensification, and both the GFDL and HWRF models predict 93L will become a hurricane, with the HWRF predicting a major hurricane. However, the SHIPS intensity model predicts only a weak tropical storm with 40 mph winds. I give 93L a 40% chance of eventually becoming a hurricane.

Steering currents are weak, but a slow northwest motion to a point just offshore the Nicaragua-Honduras border is likely through Thursday. At that time, a strong trough of low pressure will be approaching the U.S. East Coast. The models are split on whether this trough will be strong enough to pull 93L northward. The GFDL, HWRF, and ECMWF models predict the trough will turn 93L northward then northeastward, bringing the storm near the Cayman Islands by Saturday and Jamaica by Sunday. The UKMET, GFS, and NOGAPS models disagree, bringing 93L ashore over northern Nicaragua by Friday, and keeping the storm trapped near the north coast of Honduras through Monday. Given the probable center re-formation 200 miles to the north currently underway, the more northerly threat to the Cayman Islands and Jamaica appears to be the more likely scenario.

Given the current increasing trend in organization, I believe 93L will become a tropical depression on Wednesday and Tropical Storm Paloma by Thursday. NHC is giving 93L a medium (20%-50% chance) of developing into a tropical depression by Thursday morning.

Northeastern Nicaragua and northeastern Honduras are at risk of heavy rains from 93L beginning Wednesday. Total rainfall amounts of 4-8 inches are likely through Thursday in the region. These heavy rains may spread westward to the Belize border by Friday, if the storm resists being pulled northward by the trough. Panama and Costa Rica should receive only another 1-2 inches. Heavy rains will likely move into the Cayman Islands and Jamaica on Wednesday or Thursday, and may affect Cuba by Friday and Haiti by Saturday.

Currently, no models are showing a threat to Florida or the Bahamas from 93L, but that could change with the next set of model runs, after the center re-formation is taken into account. The first Hurricane Hunter flight into 93L is scheduled for Wednesday afternoon.
http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1144

[vbhoutex]

When I look at this VIS loop of 93L I see it drifting WNW or W with a center about 14N and 82 W...

will it cross into Central America?

http://metofis.rsmas.miami.edu/~dortt/s ... 1_loop.gif

Maybe it looked different earlier, but I see the obvious LLCC, albeit elongated N-S or NNW-SSE, drifting NNW to N, certainly not to the W or WNW. Different eyes will see different things.

[Blown Away]

The TAFB has this low mostly stationary for the next 72 hours and the GFDL, HWRF, and ECMWF have 93L in the NW Caribbean area just S of the Caymans in 72 hours. Clarify if I'm wrong, but based on the TAFB It seems for now the NHC is going with 93L missing the trough.

[tolakram]

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
100 PM EST TUE NOV 4 2008

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

1. A BROAD AREA OF LOW PRESSURE OVER THE SOUTHWESTERN CARIBBEAN SEA IS
DRIFTING NORTH-NORTHWESTWARD. THIS SYSTEM HAS BECOME SLIGHTLY
BETTER ORGANIZED OVER THE PAST SEVERAL HOURS...AND SOME ADDITIONAL
SLOW DEVELOPMENT IS POSSIBLE OVER THE NEXT COUPLE OF DAYS.

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

$$

FORECASTER BRENNAN/PASCH

[cycloneye]

18:00 UTC Best Track:

AL, 93, 2008110418, , BEST, 0, 136N, 817W, 20, 1008, DB,

[gatorcane]

18:00 UTC Best Track:

AL, 93, 2008110418, , BEST, 0, 136N, 817W, 20, 1008, DB,

If you loop this image, NHC has the low farther WNW:

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

If you click "NWS Fronts" you see an "L" at 14N 82W

[wxman57]

18:00 UTC Best Track:

AL, 93, 2008110418, , BEST, 0, 136N, 817W, 20, 1008, DB,

If you loop this image, NHC has the low farther WNW:

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

If you click "NWS Fronts" you see an "L" at 14N 82W

I see the low spinning right where the NHC has it - 13.6N/81.7W. If you plot the fronts on that animation it appears that the low center is off a bit compared to cloud motions. However, convection is increasing a bit north and east of that point, so it could re-form closer to the convection. In any case, there is better model agreement on a NNW track through 72 hours then a turn to the NE across the Caymans and into central to eastern Cuba then the eastern Bahamas. I still don't see a threat to Florida, as the cold front should be all the way down through the FL Straits by Sunday morning.

[gatorcane]

Thanks Wxman, yes I do agree with the position of the Low. I also see an organizing system, steady and slowly, but organizing. I see code Red within 24 hours. The center of the low is finally getting underneath the convection, the first big step in organizing.

The Latest TAFB map is very interesting. It seems to suggest they are leaning towards the latest European guidance in slowing down 93Ls northward progress. Look where it is at 72 hours -- hasn't moved much...that's 3 days from now whereas the GFS has 93L in the NW Caribbean about ready to make a turn to the NE.



and here is where the GFS puts the system in 72 hours -- a big difference:

[HURAKAN]

[Nimbus]

Sanibel wrote

I see a weak center by 13.75-81.75.

Convection is bursting just NW of that location so maybe recon will find something.

Looks like at least a TD now.

[Sanibel]

Drift west. Appearance of stronger surface formation.

[HURAKAN]

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
700 PM EST TUE NOV 4 2008

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

A BROAD AREA OF LOW PRESSURE OVER THE SOUTHWESTERN CARIBBEAN SEA IS
DRIFTING NORTH-NORTHWESTWARD. THIS SYSTEM CONTINUES TO SHOW SOME
SIGNS OF ORGANIZATION...AND COULD BECOME A TROPICAL DEPRESSION
DURING THE NEXT DAY OR TWO AS IT CONTINUES MOVING SLOWLY TO THE
NORTH-NORTHWEST OR NORTH.

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

$$

FORECASTER FRANKLIN

[HURAKAN]

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST TUE NOV 04 2008

...SPECIAL FEATURE...
A 1008 MB LOW IS IN THE CARIBBEAN OFF THE COAST OF NICARAGUA
NEAR 14N82W WITH A SURFACE TROUGH EXTENDING N TO E CUBA NEAR
20N78W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM
11N-16N BETWEEN 81W-84W...AND FROM 13N-20N BETWEEN 75W-81W. SLOW
DEVELOPMENT OF THIS SYSTEM IS POSSIBLE OVER THE NEXT COUPLE OF
DAYS.

[Blown Away]

Deep convection now popping near the LLC to the NW.
http://www.ssd.noaa.gov/goes/flt/t1/loop-avn.html

[HURAKAN]

04/2345 UTC 13.9N 81.5W T1.0/1.0 93L -- Atlantic

Best Track:

AL, 93, 2008110500, , BEST, 0, 137N, 819W, 25, 1006

[Blown Away]

wxman57, the TAFB continues to show this low pretty much stationary through 72 hours. The models continue to jet 93L off to the N then NE, why is there such a discrepancy?

http://www.nhc.noaa.gov/tafb_latest/atl ... BW_sm3.gif