[Tropical] Tropical Cyclone Discussion

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WTNT41 KNHC 210849
TCDAT1
TROPICAL STORM FAY DISCUSSION NUMBER  23
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL062008
500 AM EDT THU AUG 21 2008

AIRCRAFT RECONNAISSANCE DATA SHOW THAT FAY IS NOT STRENGTHENING.
THE HIGHEST FLIGHT-LEVEL WIND AT 850 MB FROM THE AIRCRAFT WAS 62
KT...CORRESPONDING TO SURFACE WINDS OF 50 KT...WITH PEAK ACTUAL
SURFACE OBSERVATIONS OF 50 KT FROM A DROPSONDE AND 51 KT FROM THE
SFMR.  THE PRESSURE HAS BEEN HOLDING STEADY AROUND 993-994 MB.
BASED ON THESE DATA...THE INITIAL INTENSITY ESTIMATE REMAINS 50 KT.

AFTER DRIFTING NORTHWESTWARD EARLIER TONIGHT...FAY IS NEARLY
STATIONARY AGAIN JUST A FEW MILES OFFSHORE.  A MID-LEVEL RIDGE TO
THE NORTH OF FAY...WHICH IS RESPONSIBLE FOR THE CYCLONE'S CURRENT
STALL...IS FORECAST BY THE GLOBAL MODELS TO STRENGTHEN AND BUILD
WESTWARD AS A MID- TO UPPER-LEVEL TROUGH IN THE SOUTHERN PLAINS
LIFTS OUT OVER THE NEXT TWO TO THREE DAYS.  THIS PATTERN IS
EXPECTED TO TURN FAY SLOWLY TO THE WEST-NORTHWEST ALONG THE
SOUTHERN PERIPHERY OF THE BUILDING RIDGE.  THERE HAS NOT BEEN A
GREAT DEAL OF CHANGE IN THE MODEL GUIDANCE DURING THIS FORECAST
CYCLE...ALTHOUGH THE GFS HAS SHIFTED SOUTHWARD AND NOW SHOWS A
TRACK VERY CLOSE TO THE GULF COAST OF NORTHERN FLORIDA.  THE
OFFICIAL FORECAST IS IN BEST AGREEMENT WITH THE GFS AND UKMET
GUIDANCE AND IS JUST A LITTLE BIT SOUTH OF THE PREVIOUS ADVISORY
TRACK.

THERE HAS BEEN LITTLE NET CHANGE IN THE RADAR PRESENTATION OVER THE
LAST SEVERAL HOURS...AND THE SATELLITE APPEARANCE HAS ACTUALLY
DEGRADED SLIGHTLY WITH SOME EROSION NOTED IN THE SOUTHWEST
QUADRANT. WHILE ATMOSPHERIC CONDITIONS STILL SUPPPORT SOME
INTENSIFICATION...THE BROAD STRUCTURE OF THE CYCLONE'S CORE WOULD
ARGUE AGAINST MUCH CHANGE IN STRENGTH PRIOR TO LANDFALL. ASSUMING
THAT THE TRACK FORECAST IS CORRECT IN KEEPING FAY INLAND AFTER
THAT...A GRADUAL WEAKENING WOULD BE EXPECTED. THE UPPER-LEVEL
ENVIRONMENT IS EXPECTED TO REMAIN FAVORABLE FOR REDEVELOPMENT...
HOWEVER...SHOULD FAY GO SOUTH OF THE FORECAST TRACK INTO THE GULF
OF MEXICO.

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      21/0900Z 29.1N  80.7W    50 KT
 12HR VT     21/1800Z 29.4N  81.6W    50 KT...INLAND
 24HR VT     22/0600Z 29.6N  82.5W    40 KT...INLAND
 36HR VT     22/1800Z 30.0N  83.9W    30 KT...ALONG FL GULF COAST
 48HR VT     23/0600Z 30.3N  85.1W    30 KT...INLAND
 72HR VT     24/0600Z 30.7N  87.5W    30 KT...INLAND
 96HR VT     25/0600Z 31.0N  89.0W    25 KT...INLAND
120HR VT     26/0600Z 31.0N  89.0W    25 KT...INLAND REMNANT LOW

$$
FORECASTER FRANKLIN

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