[Tropical] Tropical Cyclone Discussion

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WTNT42 KNHC 260849
TCDAT2
HURRICANE GUSTAV DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072008
500 AM EDT TUE AUG 26 2008

GUSTAV HAS CONTINUED TO INTENSIFY DURING THE LATE NIGHT HOURS. AN
AIR FORCE RESERVE RECONNAISSANCE MISSION HAS FOUND FLIGHT-LEVEL
WINDS OF 90 KT...PEAK SFMR SURFACE WINDS OF 76 KT...AND A RECENT
ESTIMATED PRESSURE OF 984 MB. THE INITIAL INTENSITY IS
CONSERVATIVELY RAISED TO 75 KT. SATELLITE IMAGES SHOW AN ORGANIZING
PATTERN WITH A CENTRAL DENSE OVERCAST BECOMING MORE PROMINENT AND
GUSTAV IS LIKELY NOT DONE INTENSIFYING BEFORE IT PASSES OVER
SOUTHWESTERN HAITI LATER TODAY.  SOME WEAKENING IS SHOWN IN 24 HR
DUE TO THE LAND INTERACTION WITH HAITI.  THEREAFTER...THE HURRICANE
IS FORECAST TO BE OVER EXTREMELY WARM WATERS WITH RELATIVELY LIGHT
SHEAR.  THE OFFICIAL INTENSITY FORECAST IS INCREASED AND NOW CALLS
FOR GUSTAV TO BE A MAJOR HURRICANE IN THE NORTHWESTERN CARIBBEAN
SEA.  IT IS WORTH NOTING THAT BOTH THE GFDL/HWRF FORECAST SHOW AN
EVEN STRONGER HURRICANE.  MOST INDICATIONS ARE THAT GUSTAV WILL BE
AN EXTREMELY DANGEROUS HURRICANE IN THE NORTHWESTERN CARIBBEAN SEA
IN A FEW DAYS.

THE INITIAL MOTION ESTIMATE IS 315/8...THOUGH GUSTAV MAY RECENTLY BE
MOVING A BIT MORE TO THE RIGHT. THE BIGGEST CHANGE TO NOTE THIS
MORNING IS A DRAMATIC SOUTHWESTWARD SHIFT WITH ALMOST ALL GUIDANCE.
A LARGE UPPER TROUGH OVER THE WESTERN ATLANTIC IS EXPECTED TO MOVE
EAST AWAY FROM GUSTAV...LEAVING RIDGING OVER THE BAHAMAS AND
FLORIDA. GLOBAL MODELS HAVE COME INTO MUCH BETTER AGREEMENT THAT
THE HURRICANE WILL TURN TO THE WEST-NORTHWEST OR EVEN WEST IN A DAY
OR SO DUE TO THIS BUILDING RIDGE. THE OFFICIAL FORECAST HAS BEEN
ADJUSTED SOUTHWESTWARD BEYOND 24 HR BUT IS STILL ON THE NORTHERN
EDGE OF THE GUIDANCE ENVELOPE.  THE FORECAST COULD HAVE BEEN
SHIFTED EVEN MORE TO THE LEFT BUT WE'D PREFER TO WAIT UNTIL THE
GUIDANCE BECOMES MORE STABLE.


FORECAST POSITIONS AND MAX WINDS

INITIAL      26/0900Z 17.2N  71.9W    75 KT
 12HR VT     26/1800Z 18.0N  72.9W    85 KT
 24HR VT     27/0600Z 18.8N  74.3W    75 KT
 36HR VT     27/1800Z 19.2N  75.6W    80 KT
 48HR VT     28/0600Z 19.4N  76.9W    85 KT
 72HR VT     29/0600Z 20.0N  79.3W    90 KT
 96HR VT     30/0600Z 21.0N  82.0W   100 KT
120HR VT     31/0600Z 23.0N  85.5W   100 KT

$$
FORECASTER BLAKE/AVILA
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