Tropical Development at Bahamas / GOM in comming days?

[Extremeweatherguy]

Here's the afternoon Houston AFD:

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
320 PM CDT SUN SEP 30 2007

.DISCUSSION...
MOISTURE STILL STREAMING NORTH THROUGH THE AREA BUT SLOWLY GETTING
PINCHED FROM THE EAST AS RIDGING EDGES IN. SHOWER(S) AND
THUNDERSTORMS SCATTERED OVER THE AREA AND MOVING INTO THE
NORTHEAST ZONES. RAINFALL ACCUMULATIONS HAVE NOT BEEN HEAVY 3-HR
AMOUNTS ONLY 1-1.5" AND HAS BEEN CONFINED TO A SMALL AREA IN SE
HARRIS AND S MATAGORDA COUNTIES. GPS IPWV OF 2-2.2" OVER THE AREA
WITH 1.65 AT LCH AT 1930Z. WATER VAPOR LOOP CLEARLY SHOWING THE
DRY AIR SPREADING OUT INTO THE SETX GULF WATER AND MOIST AXIS
BEING STRETCHED SO AM ANTICIPATING SOME LINGERING SHRA/-TSRA INTO
THE 7 PM TIME FRAME THEN DISSIPATING. OVERNIGHT THE RESIDUAL
CLOUDS AND DEVELOPING LOW CLOUD WILL HELP TO KEEP TEMPERATURES UP
TONIGHT. HIGH PRESSURE NOSES IN FROM THE EAST SHOULD DRY US OUT
AND RIDGING ALOFT WITH SUBSIDENCE SHOULD CAP THE AREA. HAVE GONE
WITH A NEARLY DRY FORECAST (EXCEPT SW ZONES) MONDAY THROUGH
WEDNESDAY. PATTERN GETS INTERESTING WITH THE UPPER TROUGH OVER NE
GULF AND FL GETTING CUT OFF...TONIGHT AND MONDAY THEN DRIFTING
WEST ACROSS THE GULF TUESDAY AND WEDNESDAY. BY WEDNESDAY THE UPPER
LOW SHOULD BE OVER THE SW GULF OR WEST GULF (GFS/ECMWF) WHILE THE
UPPER RIDGE WEAKENS AND FLATTENS. BY TUESDAY NIGHT-THURSDAY NIGHT
THE CONDITIONS OVER THE GULF WILL BE FAVORABLE FOR THE SYSTEM TO
TRANSITION FROM SUB- TROPICAL IN ORIGIN TO TROPICAL. THE TRACK IS
TROUBLESOME TO SAY THE LEAST. THE 12Z RUNS NOW BRING IT FARTHER
WEST THAN YDAY`S RUNS AND INTO SETX OR S-TX DURING THE DAY FRIDAY.
DEEPENING TROUGH OVER THE ROCKIES AND NORTHCENTRAL PLAINS SHOULD
HELP TO DRAW AT LEAST THE MOISTURE AND PERHAPS THE WHOLE SYSTEM
NORTHWARD INTO THE REGION FRIDAY. HAVE RAISED POPS STARTING FROM
EAST TO WEST THURSDAY AND THEN INCREASED CLOUDS AND MODERATED
HIGHS AND UPPED MINS. THE SYSTEM LOOKS TO BE FOLLOWED BY A FRONT
SUNDAY AND AM INCLINED TO BELIEVE THE FROPA NOW AFTER HAVING HAD
SUCH GOOD RUN TO RUN CONSISTENCY. HAVE LOWERED TEMPERATURES DAY 7
AND 8. COULD IT BE THAT WE ONLY SEE HIGHS IN THE LOWER 80S? 45 &&

Current Houston NWS mets seem to think that there is going to be a chance for a sub-tropical to tropical transition by Thursday. Could get interesting if that does take place.

[wxmann_91]

for about the 100th time this season

The global models really do not need a center to be accurate. They have the ability to actually develop a circulation

The EURO was flat out wrong with TD 10... there is a reason why I do not use that model

You can't disregard the Euro just because of one bad forecast.

The Euro outperformed all other track models in the Atlantic in 2006.
The Euro outperformed all other track models once it had Dean initialized correctly.
The Euro performed extremely well with Felix, perhaps beaten by the GFDL but it was first to see a slightly more southern track.
The Euro has been spectacular in seeing WPAC systems from far out, such as Sepat, Man-yi, Usagi, Fitow, and most recently, Lekima.
The Euro outperformed all with Sepat, getting the track AND strength (~940 mb I think it was progging) at least close to what actually transpired.

You can't argue against those stats. It's a very good model and it does exceptionally well when it has initialized the vortex well. The only area it has been subpar has been the EPAC, or when it tries to spuriously develop systems.

[Derek Ortt]

GFDL has a long track record of having very good track forecasts.

Euro was good last year when most storms quickly moved into the mid latitudes, where the EUWO excells. had a couple of good storms with Felix and Dean, but has had several total clunkers

Also, it is worth noting that the EURO does not make up part of the CONU

[Ed Mahmoud]

What he is saying, is that the NHC is quick to name a storm over the open Atlantic with only satellite to look at, but wait for recon to go into a system in the GOM/BOC or close in, when there is also surface data to confirm a system needs to be upgraded.

Well, one can argue NHC was a little slow upgrading what became Humberto. But the fact remains, aircraft can't fly missions that far out, and they can fly missions in closer, and, all else being equal, unless there was a good chance of a threat of TS winds on land anywhere within 36 hours, if an aircraft can confirm a TC before its upgraded to a TC, unless the satellite or surface observation are so conclusively overwhelmingly proof of a TC, waiting 6 hours for an aircraft to arrive doesn't seem so bad to me.

I suppose, just to be safe, if I ran things, an AC that could be cancelled in the morning might be tasked to fly a mission in the afternoon off Florida, but between buoys, radar, satellite, and obs from the Bahamas, I'd think they'd be able to spot a quicker than expected development.

And I have seen 'resource permitting' missions on just a few hours notice when things got going faster than expected.


Off to Wal-Mart opthamologist.

Correction, optometrist.

[cycloneye]

TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
530 PM EDT SUN SEP 30 2007

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

THE NATIONAL HURRICANE CENTER HAS ISSUED ITS LAST ADVISORY ON
DISSIPATING TROPICAL DEPRESSION MELISSA...LOCATED ABOUT 665 MILES
WEST OF THE CAPE VERDE ISLANDS.

A LARGE AREA OF DISORGANIZED CLOUDINESS AND A FEW THUNDERSTORMS IS
LOCATED OVER THE WESTERN ATLANTIC...BAHAMA ISLANDS...AND PORTIONS
OF SOUTH FLORIDA. THIS ACTIVITY IS ASSOCIATED WITH AN UPPER-LEVEL
TROUGH... AND A WEAK SURFACE LOW ALONG A DISSIPATING FRONTAL
BOUNDARY. SOME SLOW DEVELOPMENT OF THIS SYSTEM IS POSSIBLE DURING
THE NEXT COUPLE OF DAYS AS IT MOVES SLOWLY WESTWARD OR
WEST-SOUTHWESTWARD.

$$

FORECASTER KNABB

[Ed Mahmoud]

No invests and no TCs in the Atlantic. I wonder when that happened last?


Ok, I'm still willing to bet Steve, with the UK Met and NOGAPS on his side, $10 straight up there won't be a hurricane in Texas this week, but I will admit temperature, humidity and scattered t-storms feels more like August 30th than September 30th.

Matter of fact, I'll alter the bet that winds won't exceed storm force (not gale force) from a system classified by TPC as a pure tropical cyclone anywhere in Texas sustained on minute between 10/5/07 and 10/10/07.

Straight up, $10.

OT, anyone know what time sunset is at Kansas City today?

[Nimbus]

So we can watch for a surface circulation east of Miami from this weak surface low?

[Steve]

Like I said, no dice. Pattern setup favors Texas/Mexico impacts of whatever is out there, but I ain't about to bet straight up. In the words of former President Bush, "Not gonna do it..."

But I will wager an avatar for a week of your choosing or mine (assuming something develops).



Steve

[AJC3]

I know there were some posts near the beginning of the season about some new data buoys coming on line, however I don't know if anyone was aware of a few more that are actually up and running. I thought I'd throw them into this thread, since some of these buoys are fairly close to the surface trough axis.

http://ndbc.noaa.gov/station_page.php?station=41043
Station 41043 - SW Atlantic, 6M NOMAD buoy, 20.99 N 65.01 W (20°59'20" N 65°00'49" W)

http://ndbc.noaa.gov/station_page.php?station=41046
Station 41046 - E Bahamas, 6M NOMAD buoy, 23.9987 N 70.994 W (23°59'55" N 70°59'38" W)

http://ndbc.noaa.gov/station_page.php?station=41047
Station 41047 - NE Bahamas, 12M discus buoy at 27.47 N 71.49 W (27°28'10" N 71°29'28" W)

http://ndbc.noaa.gov/station_page.php?station=41048
Station 41048 - W Bermuda , 12M discus buoy, 31.9784 N 69.649 W (31°58'42" N 69°38'56" W)

Apologies if this is old news...but I was just made aware of 41047 being on line.

[Ed Mahmoud]

GFDL has a long track record of having very good track forecasts.

Euro was good last year when most storms quickly moved into the mid latitudes, where the EUWO excells. had a couple of good storms with Felix and Dean, but has had several total clunkers

Also, it is worth noting that the EURO does not make up part of the CONU

But is that because it isn't respected, or because it comes out about 2 hours later than the other big globals.

[southerngale]

Here's what Lake Charles afternoon discussion says about the possibility of tropical development in the GOM. It's kind of hard to believe they even mention that our forecast for the end of the week is dependent on this, since tomorrow is October.

I'm ready to start hopelessly wishing for snow!

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
353 PM CDT SUN SEP 30 2007

.LONG TERM...

ATTENTION THEN TURNS TO THE TROPICS. ALL MODELS CONTINUE TO SHOW
AN UPPER LOW CURRENTLY OVER SOUTH FLORIDA MOVING WESTWARD ACROSS
THE GULF...POTENTIALLY TAKING ON SUBTROPICAL OR TROPICAL
CHARACTERISTICS AS IT DOES. SYSTEM FORECAST TO MOVE WESTWARD
BEFORE EVENTUALLY TURNING NORTHWESTWARD TOWARDS THE TEXAS COAST
DUE TO A DEEP TROUGH DEVELOPING OVER THE WESTERN CONUS. THIS
EVOLUTION APPEARS TO BE FAIRLY SIMILAR TO THE RECENT HAPPENINGS
WITH TD #10...ALBEIT FURTHER SOUTH AND WEST...WITH LIKELY A
RATHER WEAK SURFACE LOW THE RESULT. NATURALLY FORECAST FOR THE END
OF THE WEEK WILL BE HIGHLY DEPENDANT ON WHAT DOES INDEED TAKE
PLACE WITH THIS SYSTEM. FOR NOW...APPEARS MAIN IMPACTS TO OUR CWA
WILL BE A RATHER STOUT INCREASE IN MOISTURE LEVELS THURSDAY INTO
FRIDAY...WITH ONSHORE FLOW AND LONG EASTERLY FETCH ACROSS THE GULF
ALONG WITH CONTINUED ABOVE-NORMAL TIDES POTENTIALLY CAUSING SOME
MINOR COASTAL FLOODING. HAVE INCREASED CLOUD COVER AND PRECIP
CHANCES ACCORDINGLY.

[Ed Mahmoud]

Like I said, no dice. Pattern setup favors Texas/Mexico impacts of whatever is out there, but I ain't about to bet straight up. In the words of former President Bush, "Not gonna do it..."

But I will wager an avatar for a week of your choosing or mine (assuming something develops).



Steve

What is the definition of development?

[Ed Mahmoud]

18Z GFS starting to come in, weak surface low near MIA in 36 hours.

[Steve]

>>What is the definition of development?

Minimal TS or STS. And if it comes inland in the Panhandle and subsequently retrogrades without re-entering the water, I won't count it.

Winner gets to pick the other's avatar for the subsequent week.

[Ed Mahmoud]

With PWs, based on RUC, below 1.5 inches over most of Florida, quick development, irregardless of shear, shouldn't be very quick.

[Ed Mahmoud]

If the bet doesn't count until it is already a NHC STS, you should be giving me odds.

[Ed Mahmoud]

With PWs, based on RUC, below 1.5 inches over most of Florida, quick development, irregardless of shear, shouldn't be very quick.

RUC PW is 2.1 inches at HOU, which is like August 30th.

Actual 12Z PW at CRP even higher.

[bwhorton2007]

other than a very weak low and trough i see nothing,not even any rotation from this low.

[Ed Mahmoud]

With PWs, based on RUC, below 1.5 inches over most of Florida, quick development, irregardless of shear, shouldn't be very quick.

RUC PW is 2.1 inches at HOU, which is like August 30th.

Actual 12Z PW at CRP even higher.

Edited to note

With PWs, based on RUC, below 1.5 inches over most of Florida, quick development, irregardless of shear, shouldn't be very quick.

brought to you by the Department of Redundancy Department.

[Dean4Storms]

18z GFS seems to lose the Low in the central Gulf and has it dancing all over the Gulf beforehand, strange.