[Tropical] Tropical Cyclone Discussion

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WTNT41 KNHC 160239
TCDAT1
TROPICAL STORM FAY DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL062008
1100 PM EDT FRI AUG 15 2008

WE KNOW THAT THE CENTER OF FAY IS SOMEWHERE OVER HISPANIOLA AND THE
IMMEDIATE UNKNOWN IS HOW MUCH OF FAY WILL EMERGE OVER THE CARIBBEAN
WATERS IN ABOUT 12 HOUR OR SO. BY LOOKING AT THE IMPRESSIVE
SATELLITE PRESENTATION WITH DEEP CONVECTION...OUTFLOW IN ALL
QUADRANTS AND THE STEADY WESTWARD MOTION...IT IS FAIR TO ASSUME
THAT FAY COULD SURVIVE THE HIGH MOUNTAINS OF HISPANIOLA AND
MOVE ...ALTHOUGH WEAKER...OVER THE GULF OF GONAVE SATURDAY MORNING.
IF SO...A NEW PROCESS OF INTENSIFICATION SHOULD BEGIN SINCE THE
SHEAR IS LIGHT AND THE WATERS ARE VERY WARM SOUTH OF CUBA.  ONLY
THE INTERACTION WITH THE HIGH TERRAIN OF EASTERN CUBA WOULD IMPEDE
STRENGTHENING. IN FACT...MOST OF THE INTENSITY GUIDANCE SUGGESTS
STRENGTHENING WITH THE HWRF BEING THE MOST AGGRESSIVE...MAKING FAY
A STRONG HURRICANE SOUTH OF CUBA AND EVEN A STRONGER ONE OVER THE
EASTERN GULF OF MEXICO AFTER CROSSING CUBA. THE OFFICIAL FORECAST
IS MORE CONSERVATIVE AND CALLS FOR A GRADUAL STRENGTHENING BUT
SHOWS A LITTLE MORE INTENSIFICATION THAN THE PREVIOUS FORECAST
SIMPLY BECAUSE FAY IS EXPECTED TO STAY LONGER OVER WATER IN THIS
FORECAST.

BECAUSE WE DO NOT KNOW WHERE THE CENTER IS...THE INITIAL MOTION IS
HIGHLY UNCERTAIN. THE BEST ESTIMATE OF THE INITIAL MOTION USING
CONTINUITY AND THE MOTION OF THE OVERALL CLOUD MASS IS 275 DEGREES
AT 12 KNOTS.  FAY IS FORECAST TO MOVE ON THIS GENERAL TRACK FOR
THE NEXT DAY OR SO AROUND THE SUBTROPICAL RIDGE CENTERED OVER THE
WESTERN ATLANTIC.  BUT IN 2 OR 3 DAYS...A MID-LEVEL TROUGH IS
FORECAST TO REACH THE GULF OF MEXICO ERODING THE RIDGE. THIS
PATTERN SHOULD FORCE FAY TO TAKE A MORE NORTHWESTERLY AND
NORTH-NORTHWESTERLY TRACK ACROSS CENTRAL CUBA AND THE EXTREME
EASTERN GULF OF MEXICO. ONE SHOULD MENTION HERE THAT IN
GENERAL...MOST OF THE GUIDANCE HAS SHIFTED WESTWARD AND THE
OFFICIAL FORECAST IS ON THE EASTERN EDGE OF THE ENVELOPE. BEFORE I
AM COMMITTED TO SHIFT THE TRACK FARTHER WEST...I WOULD RATHER WAIT
TO SEE IF GUIDANCE BECOMES MORE STABLE FROM ONE RUN TO THE NEXT.

IN SUMMARY...BOTH OFFICIAL FORECAST AND GUIDANCE SHOW AN
INTENSIFYING TROPICAL CYCLONE MOVING ACROSS CENTRAL CUBA AND INTO
THE EXTREME SOUTHEASTERN GULF OF MEXICO. WE MUST PAY VERY CLOSE
ATTENTION TO THE EVOLUTION OF THIS TROPICAL CYCLONE.


FORECAST POSITIONS AND MAX WINDS

INITIAL      16/0300Z 18.7N  70.8W    40 KT
 12HR VT     16/1200Z 18.8N  72.9W    35 KT
 24HR VT     17/0000Z 19.3N  75.5W    40 KT
 36HR VT     17/1200Z 20.0N  77.8W    50 KT...NEAR COAST OF CUBA
 48HR VT     18/0000Z 21.0N  79.5W    60 KT
 72HR VT     19/0000Z 24.0N  81.5W    70 KT
 96HR VT     20/0000Z 27.5N  83.0W    75 KT
120HR VT     21/0000Z 31.0N  84.0W    40 KT...INLAND

$$
FORECASTER AVILA



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