ATL: HELENE - Post-Tropical

[lrak]

This could be a feature to watch, I don't think it's actually ex td -7 because it came on shore last nite just north of Belize
Just something to watch it has a little rotation to it.

http://img89.imageshack.us/img89/4646/816y.jpg[/img]

Uploaded with ImageShack.us[/img]

Thats the one Im talking about, probably mid level spin. Looks good though

[Rgv20]

NWS Brownsville Early Morning Discussion..

"LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...WEATHER SCENARIO FOR
THE LONG TERM PORTION OF THE FORECAST BECOMING A LITTLE MORE CLEAR
NOW. GFS...EUROPEAN...AND CANADIAN MODEL GUIDANCE ALL SUGGEST THAT
A TROPICAL DISTURBANCE WILL DEVELOP ALONG THE EAST COAST OF MEXICO
EARLY TO MIDDLE OF NEXT WEEK...AND POSSIBLY AFFECT THE LOWER TEXAS
COAST. WITH DEEP TROPICAL MOISTURE INCREASING WITHIN DEEP SOUTH
TEXAS AND THE RIO GRANDE VALLEY IN ADVANCE AND IN ASSOCIATION WITH
THE POTENTIAL DISTURBANCE...AND MID-LEVEL HIGH PRESSURE REMAINING
CENTERED OVER THE DESERT SOUTHWEST...ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS ARE ANTICIPATED FOR MUCH OF THE PERIOD WITHIN
THE BRO CWFA. TEMPERATURES WILL BE KNOCKED DOWN TO MORE NEAR
NORMAL LEVELS DUE TO THE INCREASED CLOUD COVER AND OPPORTUNITIES
FOR PRECIPITATION."


HPC Morning Discussion..

MODELS SHOW AN ILL-DEFINED AREA OF LOW PRESSURE NEAR THE WRN GULF
COAST S OF TX... WITH A NUMBER OF ENSEMBLES ALSO INDICATING
POTENTIAL FOR AT LEAST A WEAK SFC CIRCULATION. THE GFS HAS
TRENDED AWAY FROM THE STRONGER DEVELOPMENT SEEN IN THE 00Z GFS RUN
FROM 24 HRS AGO. THE EARLY PRELIM FCST REFLECTS YDAYS NHC/HPC
COORDINATED TRACK FOR A WEAK SFC LOW DRIFTING NWD TOWARD EXTREME
SRN TX BY THE END OF THE PERIOD.

[cycloneye]

Is needed,recon will go on Friday afternoon.

WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
0930 AM EDT THU 16 AUGUST 2012
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 17/1100Z TO 18/1100Z AUGUST 2012
TCPOD NUMBER.....12-090

I. ATLANTIC REQUIREMENTS
1. REMNANTS OF TROPICAL DEPRESSION SEVEN
FLIGHT ONE --TEAL 73--
A. 17/2000Z
B. AFXXX 0207A INVEST
C. 17/1715Z
D. 20.8N 96.5W
E. 17/1930Z TO 17/2230Z
F. SFC TO 10,000 FT

2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.

[Houstonia]

Hou/Galv 4:55 am CDT discussion (this is the most complete discussion - the following two have just been updates):

UPPER LEVEL PATTERN REALLY HOLDS ON TO THE RIDGE OVER THE DESERT
SW WITH TROUGH AXIS FROM THE GREAT LAKES THROUGH MISS RIVER VALLEY
INTO SE TX. WITH DEEPER MOISTURE HOLDING ON AS WELL...MAIN TREND
WILL BE FOR SCT THUNDERSTORMS EACH OF MON/TUE/WED IN THE EXTENDED
FORECAST. QUITE POSSIBLE THAT LOCALLY HEAVY RAINFALL COULD TURN
INTO A FLOOD CONCERN...BUT WILL NEED TO EVALUATE RAINFALL TOTALS
OVER THE WEEKEND TO REALLY MAKE THAT DETERMINATION. THE REAL
PROBLEM MAY BE WHAT HAPPENS WITH THE TROPICAL WAVE CURRENTLY OVER
THE YUCATAN. GFS HAS BACKED OFF ON DEVELOPING THIS INTO A TROPICAL
CYCLONE BUT IF TROPICAL MOISTURE GETS FED INTO SE TX FROM THIS
WAVE...THIS MAY CONTRIBUTE TO HEAVY RAINFALL PROBLEMS. STILL LOTS
OF UNCERTAINY IN THE EXTENDED FORECAST BUT WILL KEEP 30/40 POPS
FOR EARLY NEXT WEEK AS THE SET UP STILL LOOKS FAVORABLE FOR
THUNDERSTORM ACTIVITY.

[Rgv20]

Pretty good info from the HPC Late Morning Discussion..


PRELIMINARY UPDATE...

USED THE 00Z/16 DETERMINISTIC ECMWF TO UPDATE THE PRELIMINARY
FRONTS AND PRESSURES FOR DAYS 3 THROUGH 7. THE ECMWF IS STRONGLY
CORRELATED WITH THE 00Z/16 ECENS MEAN...GEFS MEAN...AND
DETERMINISTIC GEM GLOBAL THROUGH THE PERIOD. THE 00Z/16 GFS IS OUT
OF SYNC WITH THE OTHER GUIDANCE LATE IN THE PERIOD...SHOWING ITS
BIAS OF WARMING TOO QUICKLY AND TOO SHARPLY IN THE WAKE OF THE
EASTERN TROUGH. SOUTH TEXAS CONTINUES TO BE AN AREA OF INTEREST
FOR POTENTIALLY HEAVY RAINFALL. WHETHER AN ORGANIZED TROPICAL
CYCLONE IS ABLE TO FORM OVER THE FAR WESTERN GULF OF MEXICO MAY BE
IMMATERIAL TO THE RAINFALL THREAT...WITH THE MOIST PLUME FROM THE
SOUTH INTERSECTING THE SOUTHERN EDGE OF THE WESTERLIES OVER THE
REGION. THE BIGGEST SENSIBLE WEATHER UPSHOT OF USING THE ECMWF
VERSUS THE GFS OVER THE NORTH CENTRAL STATES IS THE TENACITY OF
COOLER AIR TO THE EAST...WITH AN ENHANCEMENT TO THE BAROCLINICITY
VIA OVERRUNNING PRECIPITATION.

[tolakram]

Live visible loop: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... umframes=5

[Stormcenter]

I would watch the area crossing the Yucatan right now when it emerges into the BOC. IMO

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

[HouTXmetro]

Is that Low Level banding I'm seeing... definitely a sharp axis if not a circulation.

[Aric Dunn]

Is that Low Level banding I'm seeing... definitely a sharp axis if not a circulation.

yeah, there does appear to be a developing low level circ. small and not to the surface yet but there is also a good mid level vort with it. something to watch for sure.

[cycloneye]

2 PM TWO up to 20%

A TROUGH OF LOW PRESSURE...THE REMNANTS OF TROPICAL DEPRESSION
SEVEN...HAS EMERGED OVER THE BAY OF CAMPECHE AND CONTINUES TO
PRODUCE DISORGANIZED SHOWERS AND THUNDERSTORMS. ALTHOUGH
ENVIRONMENTAL CONDITIONS ARE CONDUCIVE FOR DEVELOPMENT...THE
PROXIMITY TO LAND WILL LIKELY LIMIT SIGNIFICANT ORGANIZATION OF
THE DISTURBANCE. THIS SYSTEM HAS A LOW CHANCE...20 PERCENT...OF
BECOMING A TROPICAL CYCLONE AGAIN DURING THE NEXT 48 HOURS AS IT
MOVES WEST-NORTHWESTWARD TO NORTHWESTWARD AT 10 TO 15 MPH.

[NDG]

The vorticity has emerged over water and is getting organized fairly quickly, IMO. Located near 19.5N & 92.7W I can see a circulation trying to get going at the surface.
I would not be surprised if by tonight's TWO chances are raised to at least 40%

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[wxman57]

That would be the area I'd keep an eye on, but the lower pressure is down along the coast of Mexico where the NHC initialized the 18Z models (18.5N/93W). No evidence of any LLC on surface obs. Easterly winds at Ciudad del Carmen on the coast of the SE BoC.

[Chickenzilla]

Thank you, Hurricaneman and tolakram!

[NDG]

12z ECMWF is fairly much a spit image of what the GFS has been persistent on for the last couple of days of possible development in the BOC then slowly moving northward along the MX coast but going inland before reaching S TX.
The GFS has nailed it again!

[Rgv20]

HPC afternoon discussion..

FINAL...

MADE MOSTLY COSMETIC CHANGES TO THE UPDATE PACKAGE FOR THE FINAL
ISSUANCE. THE 12Z/16 GUIDANCE OFFERED NO COMPELLING REASON TO
STRAY FROM THE EARLIER MODEL CHOICE. THERE IS STILL UNCERTAINTY
WITH THE DEGREE OF DEVELOPMENT OF THE DISTURBANCE ALONG THE
MEXICAN GULF COAST...THOUGH THE CHANCES FOR SIGNIFICANT RAINFALL
REMAIN OVER SOUTH TEXAS DUE TO THE SYNOPTIC PATTERN.

[Hammy]

http://www.ssd.noaa.gov/PS/TROP/floater ... -long.html

looks like some of the low cloud elements just S and SW of the 'center' could be slowing and even turning towards east movement, so this could be the beginnings of a surface circulation. I'm wondering though were this to develop there, since the primary wave axis seems to still be over Mexico, would this be TD7 again or TD9?

-personal opinion and not official forecast-

[Extratropical94]

http://www.ssd.noaa.gov/PS/TROP/floaters/07L/flash-vis-long.html

looks like some of the low cloud elements just S and SW of the 'center' could be slowing and even turning towards east movement, so this could be the beginnings of a surface circulation. I'm wondering though were this to develop there, since the primary wave axis seems to still be over Mexico, would this be TD7 again or TD9?

-personal opinion and not official forecast-

I think that as long as they call it "...THE REMNANTS OF TROPICAL DEPRESSION SEVEN..." in their TWO, they would number the area TD7 in case of regeneration.

[Zanthe]

http://www.ssd.noaa.gov/PS/TROP/floaters/07L/flash-vis-long.html

looks like some of the low cloud elements just S and SW of the 'center' could be slowing and even turning towards east movement, so this could be the beginnings of a surface circulation. I'm wondering though were this to develop there, since the primary wave axis seems to still be over Mexico, would this be TD7 again or TD9?

-personal opinion and not official forecast-

I'm almost certain it'll be TD Seven if it regenerates.

[Aric Dunn]

yeah it appears now that something at the surface is starting to get going the is a n wind on the west side and southern BOC while there is a se and south wind on the east side. low level clouds around the area of convection appear to be slowly drfiting to the east so a weak circ maybe forming rather quickly i might add. they may have to do a quick jump to 40 or 50 at 8pm and given its trend to day if it continues may be td 7 again in the morning. of course as long as it continues to organize

[wxman57]

... snip...I'm wondering though were this to develop there, since the primary wave axis seems to still be over Mexico, would this be TD7 again or TD9?
... snip

Good question. It certainly had completely lost its circulation. Not too different from TD #10 in 2005 that became TD #12 and Katrina. I was just looking at satellite images of TD 10, then remnants, then TD 12. Remnants of TD 10 in 2005 looked much more impressive between being 10 and 12 than Seven does now. That would be an argument for it becoming TD 9. However, they kept "Ivan" as Ivan many days after it lost its circulation. So who knows what they'd do?