[Tropical] Tropical Cyclone Discussion

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WTNT41 KNHC 220300
TCDAT1
TROPICAL STORM FAY DISCUSSION NUMBER  26
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL062008
1100 PM EDT THU AUG 21 2008

FAY HAS STILL REFUSED TO DECIDEDLY BEGIN MOVING WESTWARD AS WE AND
THE MODELS HAVE BEEN FORECASTING...BUT IT APPEARS TO BE DRIFTING
WESTWARD...WITH THE CENTER LOCATED JUST INLAND FROM THE NORTHEAST
FLORIDA COAST.  THE OVERALL APPEARANCE IN RADAR IMAGERY HAS
DEGRADED SLIGHTLY DURING THE PAST FEW HOURS...BUT WSR-88D
VELOCITIES SUGGEST THAT SURFACE WINDS OVER WATER TO THE SOUTH AND
EAST OF THE CENTER REMAIN AS STRONG AS ABOUT 50 KT...ALTHOUGH THAT
RADAR FEATURE HAS BEEN STEADILY SHRINKING.

EVEN THOUGH WE SAID THIS LAST NIGHT...AND IT DID NOT HAPPEN...ALL OF
THE MODEL GUIDANCE INDICATES THAT FAY SHOULD START TRULY MOVING
WESTWARD WITHIN THE NEXT SEVERAL HOURS...AS A MID-LEVEL RIDGE
BUILDS OVER THE MID-ATLANTIC STATES.  THAT RIDGE SHOULD KEEP FAY ON
A GENERAL WESTWARD TO WEST-NORTHWESTWARD PATH DURING THE NEXT FEW
DAYS.  THE MODEL CONSENSUS TRACK HAS NOT CHANGED TOO MUCH SINCE THE
LAST CYCLE...SO THE OFFICIAL TRACK REMAINS ALONG THAT OF THE
PREVIOUS ADVISORY...TAKING FAY ALONG THE FLORIDA PANHANDLE COAST.
SOME MODELS SUCH AS THE ECMWF AND HWRF CONTINUE TO FORECAST A MORE
SOUTHERLY TRACK OVER THE NORTHEASTERN GULF...WHILE THE
GFS...GFDL...AND UKMET FORECAST FAY TO REMAIN INLAND OVER THE
PANHANDLE.  LATER...AT 3 TO 5 DAYS...MOST OF THE GUIDANCE SHOWS
ANOTHER SLOWDOWN AS RIDGING BUILDS OVER THE SOUTHERN PLAINS AND
BLOCKS FAY'S FORWARD PROGRESS AGAIN.  THE NEW OFFICIAL TRACK SHOWS
ESSENTIALLY NO MOTION BEYOND 72 HOURS.

THE EXACT TRACK COULD HAVE A SIGNIFICANT IMPACT ON HOW STRONG FAY IS
AFTER CROSSING THE NORTHERN FLORIDA PENINSULA.  IF THE MORE
SOUTHERLY TRACKS ARE CORRECT AND FAY SPENDS A GOOD BIT OF TIME
CENTERED OVER THE NORTHEASTERN GULF...IT COULD RESTRENGTHEN BEYOND
24 HOURS...BUT IF THE OPPOSITE OCCURS AND IT NEVER EMERGES BACK
OVER WATER...PERMANENT WEAKENING TO A DEPRESSION COULD HAPPEN
WITHIN THE NEXT DAY OR SO.  SINCE THE OFFICIAL TRACK REMAINS ALONG
THE FLORIDA PANHANDLE COAST...AND USING THE INTENSITY MODEL
CONSENSUS AS GUIDANCE...THE NEW OFFICIAL INTENSITY FORECAST KEEPS
FAY AS A BORDERLINE TROPICAL STORM THROUGH 48 HOURS...REQUIRING THE
ISSUANCE OF NEW WATCHES AND WARNINGS ALONG THE FLORIDA GULF COAST.

REGARDLESS OF ITS EXACT TRACK...FAY WILL BE MOVING RATHER SLOWLY
DURING THE NEXT SEVERAL DAYS...POSING A SIGNIFICANT HEAVY RAINFALL
AND FLOOD HAZARD TO A VERY LARGE AREA.



FORECAST POSITIONS AND MAX WINDS

INITIAL      22/0300Z 29.3N  81.4W    50 KT
 12HR VT     22/1200Z 29.4N  82.3W    40 KT...INLAND
 24HR VT     23/0000Z 29.6N  83.7W    35 KT...OVER GULF OF MEXICO
 36HR VT     23/1200Z 30.0N  85.3W    35 KT...INLAND
 48HR VT     24/0000Z 30.4N  86.7W    35 KT...NEAR COAST
 72HR VT     25/0000Z 31.0N  88.5W    30 KT...INLAND
 96HR VT     26/0000Z 31.2N  89.0W    25 KT...INLAND
120HR VT     27/0000Z 31.5N  89.5W    25 KT...INLAND

$$
FORECASTER KNABB

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