INVEST 91L -Discussions,Analysis and Imagery

[Sanibel]

It kind of does look like an elongated LLC now. Don't see any rapid strengthening.

Big system, takes up 2/3rd's of GOM.

[Air Force Met]

if there is no closed circulation, there should not be advisories. I do not want another Thunderstorm Fay from 2002 when no VDM was ever sent back

But there is a closed circulation...of that there is no doubt.

[HouTXmetro]

As of right now This system appears to have stalled or is barely drifting. Thoughts? and whatss going on with that fron draped across the Deep South? I see storms are interacting with this system.

[Aric Dunn]

if there is no closed circulation, there should not be advisories. I do not want another Thunderstorm Fay from 2002 when no VDM was ever sent back

But there is a closed circulation...of that there is no doubt.

they found west winds on numerous passes

[Derek Ortt]

Are there no VDMs because it very poorly defined?

I'd personally perfer to wait until a VDM before upgrading

[Normandy]

As of right now This system appears to have stalled or is barely drifting. Thoughts? and whatss going on with that fron draped across the Deep South? I see storms are interacting with this system.

It has that appearance because its organized and the center is clearly trying to relocate....once it gets stacked a WNW motion should commence.

[Stormcenter]

The convention really gotten deeper and better organized in the last few hours.
The center has to be somewhere in there.

http://www.ssd.noaa.gov/goes/east/gmex/loop-avn.html

[Kludge]

A vortex message wa ssent back with Grace... something this thing does not yet have

Clue me in here, big D... recon measured surface winds from Every direction. What's it take to make a vortex?

[Air Force Met]

Are there no VDMs because it very poorly defined?

I'd personally perfer to wait until a VDM before upgrading

There have been plenty of storms upgraded without a vortex message. Grace was. She was upgraded by satellite and sfc obs...recon hadn't made it there yet....and when they did...they had a terrible time finding the center. Systems are (or used to be) upgraded all the time if it was tropical and a closed low. You didn't need a vortex. In my opinion...that is a mistake. Especially when you are starting down the barrel of the news cycle and people going to bed. Be a forecaster. If they honestly don't think it is going to develop...then don't upgrade it and wait for hard data before you do...and I am cool with that...because that is being a forecaster. If...however...you are just waiting for data...and you think it will eventually (while people are asleep)...and if it fits the criteria of TD's that have been upgraded time and time again in the past...then pull the trigger.

That is the right choice. It is the right choice for all the EOM officials out there and the public at large. Because most of them are going to bed tonight without a warning and if explosive deepening happens over-night...the average joe is going to wake up in South Texas tomorrow and be SHOCKED.

So my personal opinion is this: It looks better than other systems we have upgraded...I think it will be a TS...so there is no harm in calling it a 30 mph TD before people go to bed and putting out some watches. News casters pay attention to that more than they do the tropical weather outlook and the NHC should know it.

[ROCK]

Stormcenter - if this is not a TD right now I will eat my hat..... This has great sat presentation with intense convection, banding features becoming more pronouced by the hour

[Derek Ortt]

if the center is less defined than it was in Grace... I would perfer that it not be called a TC (yes, as everyone can see, I am very conservative in what I would classify)

[Thunder44]

CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0009 UTC WED AUG 15 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) 20070815 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
070815 0000 070815 1200 070816 0000 070816 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 23.6N 90.7W 24.5N 92.8W 25.4N 94.7W 26.4N 96.6W
BAMD 23.6N 90.7W 24.7N 92.8W 25.9N 94.9W 26.8N 96.8W
BAMM 23.6N 90.7W 24.6N 92.7W 25.7N 94.7W 26.7N 96.6W
LBAR 23.6N 90.7W 24.4N 92.7W 25.4N 95.0W 26.6N 97.2W
SHIP 25KTS 28KTS 34KTS 41KTS
DSHP 25KTS 28KTS 34KTS 33KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
070817 0000 070818 0000 070819 0000 070820 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 27.4N 98.4W 29.3N 101.5W 31.2N 103.7W 32.6N 104.3W
BAMD 27.9N 98.6W 29.6N 101.2W 31.2N 101.1W 30.9N 100.9W
BAMM 27.8N 98.5W 29.6N 101.6W 31.4N 103.1W 32.2N 103.4W
LBAR 27.9N 99.2W 29.7N 102.2W 30.6N 104.0W 30.8N 105.7W
SHIP 49KTS 64KTS 65KTS 62KTS
DSHP 29KTS 27KTS 27KTS 27KTS

...INITIAL CONDITIONS...
LATCUR = 23.6N LONCUR = 90.7W DIRCUR = 305DEG SPDCUR = 7KT
LATM12 = 22.8N LONM12 = 89.5W DIRM12 = 307DEG SPDM12 = 7KT
LATM24 = 22.1N LONM24 = 87.8W
WNDCUR = 25KT RMAXWD = 60NM WNDM12 = 25KT
CENPRS = 1006MB OUTPRS = 1010MB OUTRAD = 175NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

$$
NNNN

0z models still have it as 25kt disturbance, no upgrade likely tonight.

[Derek Ortt]

I see your point, AFM

I know that Miles Lawrence duirng Erin back in 1995 at 11 p.m. did NOT upgrade it to a hurricane because the flight level winds were 79KT, or 63.2 at the surface, even though it was forecast to become one.

I think I forecast along a similar line of thought

[Derek Ortt]

look where it was initialized.

if NHC feels that is where the center is, I can see why there is no upgrade (though I believe the center will be pulled to about 24-24.5 very very soon and then we will see some very rapid intensification tomorrow morning

[RL3AO]

32 kts FL

[Air Force Met]

if the center is less defined than it was in Grace... I would perfer that it not be called a TC (yes, as everyone can see, I am very conservative in what I would classify)

IMO this has a much better defined circulation that Grace EVER had. It was like pulling teeth to find west winds in Grace...there are west winds all over the place here. The diff with Grace was that she had a strong pressure gradient to the NE of the center and was putting down 40 kts over some oil rigs. I bet a million bucks if there was that same gradient now and some of the buoys in the GoM were showing 35 kts that they would upgrade it...regardless of how poor the LLC looked. If they found a west wind they would have pulled the trigger.

That's a fact...

[HouTXmetro]

We have been waiting on LLC relocation for almost 24 hours now.

[tailgater]

Just got back from playing B/B and was trying read the lastest post but it kinda hard. 5 pages in the last 2 hrs.
We have a TD tonite but ATM it's not bombing, pressures are falling but only slightly.
Buoy 42001
http://www.ndbc.noaa.gov/station_page.php?station=42001

[Extremeweatherguy]

FL winds up to 32 knots now and estimated surface winds as high as 36mph from the Recon. That, combined with a closed circulation is enough to warrant an upgrade IMO. Better to warn people before they go to bed.

[Derek Ortt]

In a way, this reminds me of Irene's development in 1999. Sat was very impressive but the aircraft found similar readings to today. When it developed, it went from nothing to near hurricane in about 18 hours