ATL: HELENE - Post-Tropical

[AEWspotter]

My first post. Glad to be on the boards.

I like 92L's chances, personally. It has a decent vorticity signature at 700mb. Although the 1009mb Low is officially located at 12N,35W, my bet is on something organizing a bit to the north... closer to the mid-level circulation located near 14N,36W. Despite this, I believe the system is a few days away from cyclogenesis. My guess is it will entrain some nasty air from the SAL, which could limit its development in the short term. Systems have been tracking essentially due West across the Atlantic, so I think this system has a real shot near 50W.

For what it's worth, I've been running WRF operationally off of the 00Z GFS for the East Atlantic and Africa. The latest run calls for the development of 92L after it passes 55W. It also develops the monster AEW about to exit Africa almost immediately offshore, albeit with a trajectory further to the north than the last few AEWs.

http://maloney.atmos.colostate.edu/gala ... meWRF.html

[RL3AO]

Welcome to the forum. Its very nice having an expert on African waves on here.

[cycloneye]

Welcome to Storm2k. As my collegue said, is very good to have with us an expert on that area. By the way,you can go to Talking Tropics forum and post in the thread about the big wave in West Africa your thoughts on it.

viewtopic.php?f=31&t=113281&hilit=&start=0

[KWT]

My big problem with this one is the very same lower wind issues and TUTT concerns that were present with Ernesto are still present with 92L once it reaches 55W.

Indeed with this one being a little further north I suspect it will run into that shear wall that is lurking above 15N from 55-70W currently and thats probably the main reason why none of the models keep 92L going beyond say 50-55W.

[Senobia]

Hmm. The Texas-bound 'thing' is there on the 12z, too.

As for 92L in these frames, is it the 1st or 2nd blob that curves to the right of Cuba/FL?

[ROCK]

Hmm. The Texas-bound 'thing' is there on the 12z, too.

As for 92L in these frames, is it the 1st or 2nd blob that curves to the right of Cuba/FL?

the first is whats left of Florence the 2nd is 92L....

[cycloneye]

ROCK, does the 12z Euro show in some form 92L?

[ROCK]

ROCK, does the 12z Euro show in some form 92L?

havent looked yet....but someone needs to make a GOM thread.....CMC just latched on to the NOGAPS run but instead of Texas it destroys Tampa...

[KWT]

ECM does have a very weak 92L and probably just makes it a depression before it runs into a shear wall and weakens around 96hrs time.

[ROCK]

EURO developes 92L then undevelopes it in the Carib....at 120hr

http://raleighwx.americanwx.com/models/ ... SLP120.gif

[Gustywind]

08/1745 UTC 14.1N 36.5W TOO WEAK 92L
08/1145 UTC 13.6N 34.9W TOO WEAK 92L

[Gustywind]

000
AXNT20 KNHC 081804
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED AUG 08 2012

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.

...SPECIAL FEATURE...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 35W TO THE SOUTH OF 19N.
A 1009 MB LOW PRESSURE CENTER IS ALONG THE WAVE NEAR 13.6N IN
THE MONSOON TROUGH. CONVECTIVE PRECIPITATION...SCATTERED
MODERATE TO ISOLATED STRONG IS FROM 9N TO 16N BETWEEN 33W AND
41W. THE ENVIRONMENT IS SUCH THAT THIS SYSTEM HAS A MEDIUM
CHANCE OF DEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT
48 HOURS AS IT MOVES WESTWARD 9 TO 13 KNOTS.

[drezee]

seems to me it moves it very slowly and then the wave behind erodes the ridge to make it pull NW

[tolakram]

latest visible loop

[RL3AO]

Still looks a few days away at least. You can really see those LL clouds racing west.

[tolakram]

From http://www.ssd.noaa.gov/PS/TROP/TCFP/atlantic.html

Probability is up.

[Aric Dunn]

EURO developes 92L then undevelopes it in the Carib....at 120hr

http://raleighwx.americanwx.com/models/ ... SLP120.gif

it never makes into the Caribbean... in just misses the islands the ne and starts to redevelop( actually never have weakened just low resolution) Also this run compared to the last is quite a difference the 00z run never developed it at all and loses its signature before it gets to the islands. so the euro is essentially on board with development.

[ROCK]

EURO developes 92L then undevelopes it in the Carib....at 120hr

http://raleighwx.americanwx.com/models/ ... SLP120.gif

it never makes into the Caribbean... in just misses the islands the ne and starts to redevelop( actually never have weakened just low resolution) Also this run compared to the last is quite a difference the 00z run never developed it at all and loses its signature before it gets to the islands. so the euro is essentially on board with development.

yep you are right....I was tracking a vort in the carib....it does move up and out...

[Aric Dunn]

EURO developes 92L then undevelopes it in the Carib....at 120hr

http://raleighwx.americanwx.com/models/ ... SLP120.gif

it never makes into the Caribbean... in just misses the islands the ne and starts to redevelop( actually never have weakened just low resolution) Also this run compared to the last is quite a difference the 00z run never developed it at all and loses its signature before it gets to the islands. so the euro is essentially on board with development.

yep you are right....I was tracking a vort in the carib....it does move up and out...

well 92l heads towards the bahamas and the wave over africa heads out to sea.

[cycloneye]

18z Best Track

AL, 92, 2012080818, , BEST, 0, 142N, 362W, 25, 1010, DB

ftp://ftp.nhc.noaa.gov/atcf/tcweb/inves ... 012.invest