11 PM Discussion=Interesting from Stewart about track

[cycloneye]

** WTNT41 KNHC 010242 ***
TCDAT1
HURRICANE FRANCES DISCUSSION NUMBER 29
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT TUE AUG 31 2004

RECENT RECONNAISSANCE AIRCRAFT REPORTS INDICATE THE CENTRAL PRESSURE
HAS STABILIZED TO AROUND 939-940 MB...BASED ON THE 700 MB HEIGHT
FALLS. THE MAXIMUM FLIGHT-LEVEL WIND REPORTED ON THE LAST LEG WAS
130 KT ...WHICH EQUATES TO ABOUT A 117-KT SURFACE WIND. A DROPSONDE
IN THE NORTHEAST QUADRANT ALSO REPORTED A 135-KT WIND AT ABOUT 600
FT ABOVE THE OCEAN SURFACE. CLOUD TOPS HAVE ALSO COOLED AROUND THE
EYE AND THE EYE HAS BECOME MORE DISTINCT IN BOTH SATELLITE AND
RADAR DATA...WHILE CONTRACTING DOWN TO ABOUT 20 NMI. BASED ON THIS
INFORMATION...THE INTENSITY IS BEING MAINTAINED AT 120 KT.

THE INITIAL MOTION IS NOW 285/14. THE FORECAST IS RELATIVELY CLEAR
CUT THROUGH 48 HOURS WITH MOST OF THE NHC MODEL GUIDANCE AGREEING
ON A WEST-NORTHWESTWARD MOTION TOWARD THE EAST-CENTRAL BAHAMAS.
AFTER THAT...THE MODELS DIVERGE AND DIVIDE INTO THREE DISTINCT TRACK
PATTERNS. THE GFDL AND GFDN RACE FRANCES TOWARD THE SOUTHERN COAST
OF SOUTH CAROLINA IN 96-120 HR...THE GFS...MEDIUM AND DEEP BAM...
AND UKMET MODELS TAKE FRANCES MORE SLOWLY INTO EAST-CENTRAL FLORIDA
IN 96-120 HR...WHILE THE NOGAPS...LBAR..12Z ECMWF...AND THE ETA
MODELS MOVE FRANCES ACROSS SOUTHEAST FLORIDA IN ABOUT 72 HR. THE
18Z GFDL MODEL ALSO SHIFTED WESTWARD FROM THE PREVIOUS RUN. IF THE
GFDN AND GFDL MODELS ARE IGNORED...THE REST OF THE NHC MODEL
GUIDANCE AGREES THAT THE FLORIDA EAST COAST WILL BE THE EVENTUAL
LANDFALL REGION. ONE DISTURBING PIECE OF INFORMATION IS THAT ALL OF
THE MODELS...EXCLUDING THE GFDL AND GFDN...AGREE THAT FRANCES WILL
SLOW DOWN TO LESS THAN 10 KT AFTER 72 HOURS...AND THE GFS EVEN
REDUCES THE FORWARD SPEED TO 4 KT IN 96 HR. THIS SUGGESTS THAT
STEERING CURRENTS MAY BRIEFLY COLLAPSE AS FRANCES APPROACHES THE
NORTHWESTERN BAHAMAS AND THE FLORIDA EAST COAST. THE DIFFERENCE IN
THE MODELS IS HOW THEY HANDLE THE DEEP LOW OFF THE NORTHWESTERN
U.S. COAST AS IT DIGS INTO THE CENTRAL PLAINS...AND HOW THE RIDGE
AMPLIFIES ALONG THE U.S. EAST COAST IN RESPONSE TO THAT DIGGING
LOW/TROUGH. THE GFDL HAS BEEN CONSISTENTLY INITIALIZING TOO WEAK OF
A RIDGE AROUND BERMUDA...SO LITTLE WEIGHT WAS PLACED ON THE
GFDL/GFDN SOLUTIONS. A SLIGHT WESTWARD JOG WAS PLACED IN THE
FORECAST TRACK AFTER 72-96 HR TO INDICATE SOME BUILDING OF THE
RIDGE TO THE NORTH OF FRANCES AT THAT TIME. THE OFFICIAL TRACK IS
CLOSE TO THE PREVIOUS TRACK THROUGH 72 HOURS...AND THEN A LITTLE
LEFT OF TRACK...IN ACCORDANCE WITH THE GUNA CONSENSUS MODEL.

THE INTENSITY FORECAST REMAINS UNCHANGED. THE SHIPS MODEL PEAKS
FRANCES AT 124 KT IN 12-24 HOURS...THEN WEAKENS THE HURRICANE DOWN
TO 112 KT IN 72 HOURS. HOWEVER...THIS WEAKENING IS CAUSED BY
'SELF-INFLICTED' VERTICAL SHEAR SINCE THE OFFICIAL FORECAST TRACK
IS SOUTH OF THE GFS TRACK...PLACING THE HURRICANECENTER IN STRONG
CYCLONIC WESTERLY OUTFLOW ON THE SOUTH SIDE OF THE GFS MODEL STORM.

FORECASTER STEWART

FORECAST POSITIONS AND MAX WINDS

INITIAL 01/0300Z 20.8N 67.0W 120 KT
12HR VT 01/1200Z 21.7N 69.1W 125 KT
24HR VT 02/0000Z 22.8N 71.4W 130 KT
36HR VT 02/1200Z 24.0N 73.5W 130 KT
48HR VT 03/0000Z 25.2N 75.5W 130 KT
72HR VT 04/0000Z 26.8N 78.3W 125 KT
96HR VT 05/0000Z 28.0N 81.0W 100 KT...INLAND
120HR VT 06/0000Z 31.0N 82.5W 55 KT...INLAND

[dhweather]

It's back to the rule I follow - don't trust the models beyond 72 hours!

[Brent]

[cycloneye]

The entire east coast of Florida may get a hurricane watch as early as tommorow.

[Brent]

The entire east coast of Florida may get a hurricane watch as early as tommorow.

Probably. Late tomorrow.

[boca]

I have that sick to my stomach feeling like you had when you thought Charley was coming to you and I have to admit I scared.

[Brent]

I'm wondering if it'll turn as sharp as the NHC projects. We're talking about a Cat 4 here. It's a lot harder for it to turn than it is for a weak system.

[dwinpcola]

Ok , I am fairly new here but not to storms. I am here in the panhandle and have been following the storm. My concern is the continued west movemnet and speed. Is there much thought of the storm heading to the central gulfcoast. I have seen some models that bring the storm to this general area after crossing central/southern florida.

Looking for some input for the gang here

dw

[btangy]

That was a very good discussion tonight. For once it mentioned ALL the models and not just the GFS, UKMET, and GFDL. And they actually discounted the GFDL model this time. Thank you!

[B-Bear]

Ok , I am fairly new here but not to storms. I am here in the panhandle and have been following the storm. My concern is the continued west movemnet and speed. Is there much thought of the storm heading to the central gulfcoast. I have seen some models that bring the storm to this general area after crossing central/southern florida.

Looking for some input for the gang here

dw

IF Frances hits south Florida, I believe it will be likely that she will emerge in the Gulf only to once again make landfall very quickly, somewhere along MS or the FL panhandle.

[x-y-no]

That was a very good discussion tonight. For once it mentioned ALL the models and not just the GFS, UKMET, and GFDL. And they actually discounted the GFDL model this time. Thank you!

Yeah. Stewart is the best.

[Steve Cosby]

That was a very good discussion tonight. For once it mentioned ALL the models and not just the GFS, UKMET, and GFDL. And they actually discounted the GFDL model this time. Thank you!

Stacy Stewart seems to have the best discussions over and over.

Isn't he the young stud of the bunch (sorta, anyway)?

[lookout]

Ok , I am fairly new here but not to storms. I am here in the panhandle and have been following the storm. My concern is the continued west movemnet and speed. Is there much thought of the storm heading to the central gulfcoast. I have seen some models that bring the storm to this general area after crossing central/southern florida.

Looking for some input for the gang here

dw

IF Frances hits south Florida, I believe it will be likely that she will emerge in the Gulf only to once again make landfall very quickly, somewhere along MS or the FL panhandle.

I really dont believe for a second that Frances will get that far west. fact is the hurricane center used an average of their available guidance to issue this track. But has anyone noticed the output of the bam? both the medium and deep bam has frances moving pretty far north/northwest then suddenly (in response to increased surface ridging due to digging trough out west temperarly?)then hooks the storm pretty hard left into central florida. This has caused the guna to switch further south. IF that left hook was not there, the bam would indicate a landfall quite a bit further north somewhere near jacksonville i presume. This left turn by the bam model seems rather suspecious to me to say the least. i still believe jacksonville to daytona will be the landfall area and i dont see anything to change that. it shoudl be interesting to see the next few runs and what the models do around the central and northern bahamas.