553
WTNT42 KNHC 111434
TCDAT2
HURRICANE FRED DISCUSSION NUMBER 16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072009
1100 AM AST FRI SEP 11 2009
THE CLOUD PATTERN HAS BEEN GRADUALLY DETERIORATING SINCE YESTERDAY
AND HAS BECOME EVEN MORE ELONGATED DUE TO SHEAR. MICROWAVE DATA
SHOWS THAT THE CENTER IS LOCATED ON THE SOUTHERN PORTION OF THE
DEEP CONVECTION WITH SIGNIFICANT OUTFLOW ONLY TO THE NORTH. THE
INITIAL INTENSITY HAS BEEN LOWERED TO 70 KNOTS BASED ON 4.0 AND 4.5
DVORAK T-NUMBERS FROM SAB AND TAFB...AND A QUIKSCAT PASS OVER THE
CYCLONE EARLIER TODAY. WATER VAPOR IMAGES SHOW MASSIVE UPPER-LEVEL
WESTERLY AND SOUTHWESTERLY FLOW FROM THE CARIBBEAN EASTWARD ACROSS
THE TROPICAL ATLANTIC ASSOCIATED WITH A STRONGER THAN NORMAL
MID-OCEANIC TROUGH. IT IS HIGHLY UNLIKELY THAT FRED WILL SURVIVE
SUCH HOSTILE UPPER-LEVEL ENVIRONMENT. THEREFORE...WEAKENING IS
FORECAST.
FRED IS EMBEDDED WITHIN VERY LIGHT STEERING CURRENTS. IT IS
BASICALLY DRIFTING NORTHWARD AND NO SIGNIFICANT MOTION IS EXPECTED
DURING THE NEXT DAY OR TWO. THEREAFTER...GLOBAL MODELS DEVELOP A
SUBTROPICAL RIDGE OVER THE NORTHEASTERN ATLANTIC AND THIS PATTERN
WILL PROVIDE SOME WEST-NORTHWESTWARD STEERING TO WHATEVER IS LEFT
OF THE CYCLONE. TRACK GUIDANCE RESPONDS TO THE LIGHT STEERING FLOW
BY KEEPING FRED MEANDERING FOR THE NEXT TWO DAYS...AND TO THE
DEVELOPMENT OF THE RIDGE BY MOVING THE CYCLONE OR ITS REMNANTS
WESTWARD. THE OFFICIAL FORECAST FOLLOWS THE GUIDANCE TREND.
FORECAST POSITIONS AND MAX WINDS
INITIAL 11/1500Z 18.0N 35.0W 70 KT
12HR VT 12/0000Z 18.1N 34.8W 60 KT
24HR VT 12/1200Z 18.2N 34.6W 50 KT
36HR VT 13/0000Z 18.5N 34.5W 40 KT
48HR VT 13/1200Z 19.0N 35.0W 30 KT
72HR VT 14/1200Z 20.5N 38.5W 25 KT
96HR VT 15/1200Z 22.0N 43.5W 20 KT...REMNANT LOW
120HR VT 16/1200Z 23.0N 49.0W 20 KT...REMNANT LOW
FORECASTER AVILA
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page