000 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