ATL: KARL - Ex-Hurricane - Discussion

[Brent]

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT MON SEP 13 2010

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

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON HURRICANE
IGOR...LOCATED ABOUT 1000 MILES EAST OF THE NORTHERN LEEWARD
ISLANDS...AND ON RECENTLY UPGRADED TROPICAL STORM JULIA...LOCATED
ABOUT 60 MILES SOUTH-SOUTHEAST OF THE SOUTHERNMOST CAPE VERDE
ISLANDS.

CLOUDINESS AND SHOWERS REMAIN DISORGANIZED IN ASSOCIATION WITH A
TROUGH OF LOW PRESSURE OVER THE CENTRAL CARIBBEAN SEA.
ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR SOME DEVELOPMENT
DURING THE NEXT COUPLE OF DAYS AS THE TROUGH MOVES WEST-
NORTHWESTWARD AT 10 TO 15 MPH. THERE IS A MEDIUM CHANCE...40
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS. REGARDLESS OF DEVELOPMENT...LOCALLY HEAVY RAINFALL
IS POSSIBLE OVER PORTIONS OF HISPANIOLA... JAMAICA...AND CUBA
DURING THE NEXT DAY OR TWO. THESE RAINS COULD CAUSE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES...ESPECIALLY IN
MOUNTAINOUS TERRAIN.

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

PUBLIC ADVISORIES ON JULIA ARE ISSUED UNDER WMO HEADER WTNT32 KNHC
AND UNDER AWIPS HEADER MIATCPAT2. FORECAST/ADVISORIES ARE ISSUED
UNDER WMO HEADER WTNT22 KNHC AND UNDER AWIPS HEADER MIATCMAT2.

$$
FORECASTER CANGIALOSI/PASCH

[Shuriken]

The eastern Caribbean is now being bulldozed by exhaust from Igor; it's entirely possible he snuffs 92L before it develops:

(Time-sensitive) http://www.ssd.noaa.gov/goes/east/catl/flash-wv.html

[ColinDelia]

Vorticity has been weaker the past 24 hours than previously. As of right now there is no 850 mb vorticity being analyzed of 50 units or higher.
Interestingly the vorticity at 700 mb looks a little stronger and I think this has been the case for the past day or so. So far, the story of 92L has been of
a circulation in the low middle levels having difficulty getting down to the surface.

One interesting thing though. The vorticity at 500 mb has increased the past half day; though it has elongated somewhat the past 3 hours.

[Nimbus]

Convection flare up over Jamaica this morning. These sem to be occurring farther and farther north. might mean more time over the water in the gulf.

[cycloneye]

8 AM TWO remains at 40%.

A TROUGH OF LOW PRESSURE OVER THE CENTRAL CARIBBEAN SEA CONTINUES TO
PRODUCE DISORGANIZED CLOUDINESS AND SHOWERS. ENVIRONMENTAL
CONDITIONS APPEAR TO BE CONDUCIVE FOR SOME DEVELOPMENT DURING THE
NEXT COUPLE OF DAYS AS THE TROUGH MOVES WEST-NORTHWESTWARD AT
AROUND 15 MPH. THERE IS A MEDIUM CHANCE...40 PERCENT...OF THIS
SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
REGARDLESS OF DEVELOPMENT...LOCALLY HEAVY RAINFALL IS POSSIBLE OVER
PORTIONS OF HISPANIOLA...JAMAICA...CUBA...AND THE CAYMAN ISLANDS
DURING THE NEXT DAY OR TWO. THESE RAINS COULD CAUSE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES...ESPECIALLY IN
MOUNTAINOUS TERRAIN.

[KWT]

Intersting Nimbus but it probably doesn't mean an awful amount other then there is probably better divergence/convergence to the north of the system, of course it may make a difference but we will see.

At least we have very strong model support for weak development before Yucatan followed by stronger development in the BoC and maybe S.Gulf...

As for track, pretty good agreement on a WNW into the Yucatan followed by probably a bend back westwards into Mexico....if it does follow that track and develop, we'd probably get a hurricane in the BoC like we saw with Alex.

[cycloneye]

12z Best Track

AL, 92, 2010091312, , BEST, 0, 162N, 772W, 25, 1006, DB

[Sanibel]

I'd put the center near 16N-77W by visible satellite. Still has enough of a convection tag to offer the threat of development in the west Caribbean. More west now in direction.

[O Town]

Darn close, as of 13z 16.60N, 76.50W
http://cimss.ssec.wisc.edu/tropic2/predict/#

[caneman]

Well, it does look as if the Southern models won out on this one as it didn't go over Jamaica or North of it as I had predicted. If it continues due West, there may be some land interaction with Central America which could prevent much development. I don't really see how this would have enough time (moving at 15 mph) or space to become anything more than a Cat. 1 at best but more likely a high end T.S.

[HURAKAN]

Based on the RECON reports, winds are a little stronger than what they found yesterday, but there's not even a hint of a west wind.

[HURAKAN]

producing strong convection

[TYNI]

Based on the RECON reports, winds are a little stronger than what they found yesterday, but there's not even a hint of a west wind.

Hurakan - I assume no west wind = no apparent circulation at the moment?

Not sure this has time to get organized before the Yucatan shreds it.

[dwsqos2]

I can see the benefit of a flight at the 650 mb level in order to sample the entire column or air, but really, it didn't tell me anything I didn't know already from watching visible satellite trends. That is, the system is not very well organized aloft and not much better at the surface. However, I do see evidence of perhaps a bit more low-level convergence, so my confidence continues to grow in the eventual development of the system. Pressures have risen at buoy 42057; however, as of 1450Z the pressure observed was 29.83 in. Yesterday, at 1450Z the observed pressure was 29.87 in. Winds are currently out of the NNE (30 degrees) at 11.7 knots.

http://www.ndbc.noaa.gov/station_page.php?station=42057

[dwsqos2]

Not sure this has time to get organized before the Yucatan shreds it.

In general, land interaction's negative effects on a system are directly proportional to its strength. That is a weaker system is less negatively impacted. Also, the Yucatan, given that it's so flat, pretty much never destroys storms. Remember that Alex's pressure at landfall in Belize was 996 mb; upon exiting the first pressure observed was 990 mb. The disturbance that preceeded Marco organized while over the Yucatan. Opal became a tropical storm while over the Yucatan, though it passed over the extreme northern portion. Granted 92L won't have quite Alex's upper-level support, but 200 mb winds look rather nice for development.

EDIT-Also, it may be nothing more than a surface trought upon passing over the Yucatan, and those pass over the Yucatan without a scratch all the time.

[caneman]

Doubtful at its speed of movement and present state that it will have much if any time to really do much of anything. Hopefully it continues moving as fast as it is so as not to cause any flooding.

[lrak]

It looks like the large bottom blob is racing to the SW and the one by Jamaica is starting to build up again.

[KWT]

Possibly has time to become a TD but I'd be surprised if it got any stronger then that...but don't underestimate what the NW Caribbean for powering up developing systems, Alex looked many times worse at this point and made it so no reason this can't.

Even if it doesn't conditions look good in the BoC right now for development or strengthening.

[hurricaneCW]

It will probably wait until it gets to the BOC and then blow up Hermine or Alex style.

[HURAKAN]

Based on the RECON reports, winds are a little stronger than what they found yesterday, but there's not even a hint of a west wind.

Hurakan - I assume no west wind = no apparent circulation at the moment?

Not sure this has time to get organized before the Yucatan shreds it.

visible images suggest there may be a MLC, but RECON reports no LLC. Yucatan is unlikely to shred anything.