INVEST 91L -Discussions,Analysis and Imagery

[Derek Ortt]

very well-defined LLC now just SW of the convection

I doubt that this reforms to the NE now

[tailgater]

very well-defined LLC now just SW of the convection

I doubt that this reforms to the NE now

Doesn't look like it will get stacked anytime soon, as the mid-level circulation well north of Cancun looks pretty vigorous this morning.

[Nimbus]

From the 5 AM TD4 discussion:

By days 4-5...models begin to diverge
due to differing forecasts of an mid/upper-level cutoff low
expected to form off the southeastern United States coast.

This would indicate that there was also some uncertainty about ridging in the gulf, since a cut off low usually has a high to its west. As long as the surface feature continues to move WNW at 10 - 15 MPH I don't see a problem. At that speed there will be some shear from the Texas ULL and not enough time to develop.

The NHC officials have not yet embraced Arics' double jet outflow scenario. For that scenario to verify the system would have to stall and build under a gulf ridge.

[Matt-hurricanewatcher]

Its moving northwestward based on the latest satellite. With convection forming over its northern side. Could be a depression today.

[WindRunner]

Its moving northwestward based on the latest satellite. With convection forming over its northern side. Could be a depression today.

LLC can be seen moving due west (don't let the mid-level clouds distract you) at around 22N/89W . . . and all of that little bit of convection popping on the north side is getting knocked off by the ULL that is still too close to allow for outflow enhancement. On the good side, the ULL is just barely moving faster than our LLC is, so conditions should be slowly improving over the next few hours . . . possibly for a TD declaration at 5pm, post-recon.

[HURAKAN]

I think we could have the fifth depression later today.

[WindRunner]

I'm sure you see the 1006mb/20kt ob in the convection . . . certainly a good thing to at least know that the pressure is almost certainly still dropping . . .

[Matt-hurricanewatcher]

I do see what I'm seeing. Maybe not a northwest but more west-northwest then it was. I would place the LLC near 22.5-22.8 north/89-89.5 west. Convection is starting to form to the east and north side. As the upper low moves away expect this to develop.

[HURAKAN]

[Matt-hurricanewatcher]

Gfdl takes it to 27-27.5 north into Texas. In makes it a strong tropical storm/cat1 hurricane. It is not out of the picture that this thing could strengthen at a "nice" rate once the upper level low moves out of the way.

[tailgater]

Surface obs from just south of the center. Merida
http://weather.noaa.gov/weather/current/MMMD.html

[Steve]

>> it looks pathetic right now.

At that time, it looked like a sheared system on an IR because that's what it was. It looked exactly like what it was at the stage it was in.
-------------------------------------
Hey AFM,

Glad to have you back from vacation.

Steve

[Portastorm]

System looks much, MUCH better this morning ... that is if you're rooting for organization.

Low-level center established, nice outflow ... I think we have GAME ON.

[KatDaddy]

ULL almost moving onto TX Coast

http://www.ssd.noaa.gov/goes/east/gmex/wv-l.jpg

Plenty of low shear for development today and lots of tropical moisture headed into TX and SW LA.

[Portastorm]

Anyone seen the latest SHIPS data on 91L?

Given how quickly it ramped up in the last 8 hrs, I'm a little worried now about a rapidly developing storm. Wouldn't be the first time in the WGOM.

[Matt-hurricanewatcher]

It would not suprize me if this got its self together. 1# as the upper low moves out to the west, this system will form a northwest outflow channel. 2# very very hot water to feed on.

Its possible the Gfdl is right.

[Aquawind]

981
WHXX01 KWBC 140647
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0647 UTC TUE AUG 14 2007

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

DISTURBANCE INVEST (AL912007) 20070814 0600 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
070814 0600 070814 1800 070815 0600 070815 1800

LAT LON LAT LON LAT LON LAT LON
BAMS 22.2N 88.4W 23.1N 90.5W 23.7N 92.8W 24.7N 95.2W
BAMD 22.2N 88.4W 23.2N 90.7W 24.3N 93.0W 25.3N 95.6W
BAMM 22.2N 88.4W 23.2N 90.7W 24.1N 93.1W 25.3N 95.7W
LBAR 22.2N 88.4W 22.8N 90.2W 23.7N 92.7W 24.8N 95.3W
SHIP 30KTS 37KTS 44KTS 52KTS
DSHP 30KTS 37KTS 44KTS 52KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
070816 0600 070817 0600 070818 0600 070819 0600

LAT LON LAT LON LAT LON LAT LON
BAMS 25.6N 97.5W 26.8N 101.5W 27.8N 105.1W 28.5N 107.6W
BAMD 26.4N 98.0W 28.4N 102.0W 29.9N 104.6W 30.1N 105.4W
BAMM 26.3N 98.1W 28.0N 102.1W 29.2N 105.5W 29.8N 107.2W
LBAR 26.2N 98.0W 29.2N 102.2W 31.1N 104.1W 31.4N 104.0W
SHIP 57KTS 72KTS 79KTS 73KTS
DSHP 43KTS 28KTS 27KTS 27KTS

...INITIAL CONDITIONS...
LATCUR = 22.2N LONCUR = 88.4W DIRCUR = 285DEG SPDCUR = 8KT
LATM12 = 21.9N LONM12 = 86.9W DIRM12 = 287DEG SPDM12 = 9KT
LATM24 = 21.2N LONM24 = 84.9W
WNDCUR = 30KT RMAXWD = 75NM WNDM12 = 25KT
CENPRS = 1007MB OUTPRS = 1009MB OUTRAD = 130NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

$$
NNNN

[tailgater]

I don't see where this systems is getting it's act together very much, it still has a basically exposed low level circ. and a md level circ. well to the NE. I also doubt it will hit the Texas coast.

[Thunder44]

I don't see where this systems is getting it's act together very much, it still has a basically exposed low level circ. and a md level circ. well to the NE. I also doubt it will hit the Texas coast.

Latest satellite image I saw where thunderstorms forming NW of the center, and thunderstorm from the NE, moving closer to the center.

[HURAKAN]

Convection continues to develop just NW of the LLC.