[Tropical] Tropical Cyclone Discussion

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WTNT41 KNHC 161507
TCDAT1
TROPICAL STORM FAY DISCUSSION NUMBER   4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL062008
1100 AM EDT SAT AUG 16 2008

VISIBLE SATELLITE IMAGERY SHOWS THAT THE CENTER OF FAY IS NOW OVER
WATER TO THE NORTH OF THE SOUTHWESTERN PENINSULA OF HAITI...WITH
LITTLE ORGANIZED CONVECTION NEAR THE CENTER AT THIS TIME.  WHILE
THE STORM PRODUCED A LARGE CONVECTIVE BURST DURING THE NIGHT OVER
THE WATER SOUTH OF THE PENINSULA...MICROWAVE IMAGERY SHOWS THIS
BURST WAS AT THE FAR END OF A CONVECTIVE BAND AND NOT DIRECTLY
ASSOCIATED WITH THE CENTER.  SATELLITE INTENSITY ESTIMATES FROM
TAFB AND SAB REMAIN 35 KT...AND THE INITIAL INTENSITY REMAINS 40 KT
BASED ON CONTINUITY FROM THE LAST ADVISORY.  AN AIR FORCE RESERVE
HURRICANE HUNTER AIRCRAFT WILL INVESTIGATE FAY AROUND 18Z TO
PROVIDE BETTER DATA ON THE INTENSITY AND STRUCTURE.

THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 280/13.  FAY REMAINS ON
THE SOUTH SIDE OF A LOW/MID-LEVEL RIDGE...WITH THE LARGE-SCALE
MODELS FORECASTING A WEAKNESS IN THE RIDGE OVER THE EASTERN GULF OF
MEXICO OR FLORIDA THAT SHOULD ALLOW FAY TO TURN TOWARD THE
NORTH-NORTHWEST OR NORTH AFTER 36 HR.  THERE IS A LARGE SPREAD IN
THE MODEL GUIDANCE ON WHEN AND HOW SHARPLY FAY WILL TURN.  THE
ECMWF...CANADIAN...AND NAM ARE FARTHEST TO THE EAST...CALLING FOR
FAY TO MOVE ACROSS CUBA TO THE SOUTHEASTERN COAST OF FLORIDA.  THE
GFDL IS A LITTLE FARTHER WEST.  THE GFS...HWRF...FLORIDA STATE
SUPERENSEMBLE...AND THE CONSENSUS MODELS FORECAST FAY TO CROSS WEST
CENTRAL CUBA AND MAKE LANDFALL ALONG THE SOUTHWEST COAST OF
FLORIDA.  THE UKMET AND GFDN ARE FARTHER WEST...FORECASTING FAY TO
MOVE TOWARD THE FLORIDA PANHANDLE.  THE NOGAPS IS THE FARTHEST
WEST...FORECASTING FAY TO MOVE TOWARD THE NORTHERN GULF COAST.
OVERALL...THE GUIDANCE ENVELOPE AND THE MODEL CONSENSUS HAS SHIFTED
A LITTLE TO THE EAST SINCE THE LAST ADVISORY.  THUS...THE NEW
FORECAST TRACK IS NUDGED A BIT TO THE EAST OF THE PREVIOUS TRACK
AFTER 48 HR.  EVERYONE IN THE FLORIDA PENINSULA SHOULD MONITOR THE
PROGRESS OF FAY...AS MOST LOCATIONS THERE HAVE ABOUT THE SAME
CHANCES OF EXPERIENCING HURRICANE-FORCE WINDS ACCORDING TO THE NHC
WIND SPEED PROBABILITY PRODUCT.

WHEN FAY IS OVER WATER...IT APPEARS THAT ATMOSPHERIC CONDITIONS WILL
BE FAVORABLE FOR STRENGTHENING THROUGH 72 HR.  THUS...THE INTENSITY
WILL BE CONTROLLED BY LAND INTERACTION AND THE RESULTING IMPACTS ON
THE STORM STRUCTURE.  ALL GUIDANCE FORECASTS STRENGTHENING...AND
THE INTENSITY FORECAST FOLLOWS SUIT IN BEST AGREEMENT WITH THE
SHIPS MODEL.  HOWEVER...THIS IS A LOW CONFIDENCE INTENSITY
FORECAST.  FAY COULD STRENGTHEN RAPIDLY IF IT BECOMES WELL
ORGANIZED OVER WATER.  ON THE OTHER HAND IT MIGHT NOT STRENGTHEN
MUCH AT ALL IF LAND INTERACTION PREVENTS ORGANIZATION.


FORECAST POSITIONS AND MAX WINDS

INITIAL      16/1500Z 19.0N  73.7W    40 KT
 12HR VT     17/0000Z 19.3N  75.4W    45 KT
 24HR VT     17/1200Z 20.0N  77.5W    50 KT...INLAND
 36HR VT     18/0000Z 21.1N  79.3W    55 KT
 48HR VT     18/1200Z 22.7N  80.6W    65 KT...INLAND
 72HR VT     19/1200Z 26.0N  82.0W    80 KT
 96HR VT     20/1200Z 29.5N  82.5W    60 KT...INLAND
120HR VT     21/1200Z 32.5N  83.0W    35 KT...INLAND

$$
FORECASTER BEVEN




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