[Tropical] Tropical Cyclone Discussion

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WTNT41 KNHC 220905
TCDAT1
TROPICAL STORM FAY DISCUSSION NUMBER  27
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL062008
500 AM EDT FRI AUG 22 2008

SATELLITE...RADAR...AND SURFACE OBSERVATIONS SHOW LITTLE CHANGE IN
THE STRUCTURE OF FAY DURING THE PAST SEVERAL HOURS...WITH THE
STRONGEST WINDS 50 N MI OR MORE FROM THE CENTER AND THE STRONGEST
RAINBANDS OVER THE ATLANTIC WELL TO THE EAST OF THE CENTER.
WSR-88D DOPPLER WINDS DATA SUGGEST A SLIGHT DECREASE IN THE
INTENSITY...WHICH IS SET AT 45 KT IN THIS ADVISORY.  THE CIRRUS
OUTFLOW IS GOOD IN THE NORTHERN SEMICIRCLE AND FAIR TO POOR
ELSEWHERE.

FAY HAS MOVED A LITTLE FASTER DURING THE PAST 6 HR WITH THE INITIAL
MOTION OF 280/5.  THE CYCLONE IS ON THE SOUTH SIDE OF AN AMPLIFYING
DEEP-LAYER RIDGE OVER THE EASTERN UNITED STATES...AND THE
LARGE-SCALE MODELS FORECAST THIS FEATURE TO PERSIST FOR THE NEXT
48-72 HR.   THIS PATTERN SHOULD CAUSE FAY TO MOVE SLOWLY
WESTWARD...WITH ALL TRACK GUIDANCE AGREEING WITH THIS SCENARIO.
THE NEW FORECAST TRACK CALLS FOR FAY TO MOVE A LITTLE FARTHER WEST
THAN PREVIOUSLY...AS THE GUIDANCE SHOWS A MORE WESTWARD MOTION
BETWEEN 48 AND 72 HR THAN IT DID 6 HR AGO.  AFTER 72 HR...
MID/UPPER-LEVEL TROUGHING OVER THE CENTRAL UNITED STATES IS
FORECAST TO WEAKEN THE RIDGE...WHICH SHOULD ALLOW FAY TO TURN
NORTHEASTWARD OR EASTWARD.  THE GUIDANCE SHOWS CONSIDERABLE SPREAD
AT THIS POINT...SO THE TRACK FORECAST WILL CALL FOR A SLOW
NORTHEASTERLY MOTION.

DUE TO FAY'S PROXIMITY TO LAND...THE INTENSITY FORECAST IS DEPENDENT
ON THE EXACT TRACK AND STRUCTURE.  ON THE FORECAST TRACK...FAY WILL
NOT LIKELY BE OVER WATER LONG ENOUGH TO INTENSITY.  ON THIS
BASIS...THE INTENSITY FORECAST CALLS FOR THE SYSTEM TO MOVE ALONG
THE NORTHERN GULF COAST AS A MINIMAL TROPICAL STORM.  IF FAY MOVES
TO THE RIGHT OF THE FORECAST TRACK...IT WILL MOVE INLAND EARLIER
AND WEAKEN FASTER.  IF IT MOVES LEFT OF THE FORECAST TRACK MORE
OVER OPEN WATER...IT COULD GET STRONGER THAN FORECAST.  HOWEVER...
THE CURRENT BROAD STRUCTURE IS LIKELY TO PRECLUDE RAPID
INTENSIFICATION.  THE LARGE-SCALE MODELS FORECAST WESTERLY SHEAR TO
IMPACT FAY STARTING IN ABOUT 72 HR...WHICH SHOULD STOP
INTENSIFICATION REGARDLESS OF WHETHER IT IS OVER WATER OR NOT.

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      22/0900Z 29.6N  82.2W    45 KT...INLAND
 12HR VT     22/1800Z 29.7N  83.2W    40 KT...INLAND
 24HR VT     23/0600Z 29.8N  84.6W    35 KT
 36HR VT     23/1800Z 30.1N  86.1W    35 KT
 48HR VT     24/0600Z 30.5N  87.5W    35 KT...INLAND
 72HR VT     25/0600Z 31.0N  89.5W    30 KT...INLAND
 96HR VT     26/0600Z 31.0N  90.0W    25 KT...INLAND
120HR VT     27/0600Z 32.0N  89.5W    20 KT...INLAND REMNANT LOW

$$
FORECASTER BEVEN

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