[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT45 KNHC 132019
TCDAT5
TROPICAL DEPRESSION TEN DISCUSSION NUMBER   1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT SAT AUG 13 2005

SATELLITE IMAGES INDICATE THAT THE AREA OF LOW PRESSURE THAT
DEVELOPED IN ASSOCIATION WITH A TROPICAL WAVE IN THE ATLANTIC...EAST
OF THE LESSER ANTILLES... HAS BECOME BETTER ORGANIZED...AND BASED
ON DVORAK CLASSIFICATIONS FROM BOTH TAFB AND SAB THE SYSTEM HAS
BEEN UPGRADED TO TROPICAL DEPRESSION STATUS.

CURRENTLY...THE DEPRESSION HAS A LARGE AREA OF CONVECTION WITH SOME
CURVED BANDS AND OUTFLOW EXPANDING WESTWARD. HOWEVER...THIS
FAVORABLE ENVIRONMENT MAY NOT LAST FOR LONG. UNANIMOULSY...ALL
GLOBAL MODELS ARE DEVELOPING A RATHER STRONG AND UNUSUALLY DEEP
UPPER-TROUGH BETWEEN THE LEEWARD ISLANDS AND THE DEPRESSION. THIS
TROUGH WILL LIKELY PRODUCE A HOSTILE ENVIRONMENT FOR THE DEPRESSION
TO STRENGTHEN SIGNIFICANTLY. SHIPS MODEL FORECAST A GRADUAL
INTENSIFICATION...AND THE GFDL THAT FOR THE PAST FEW RUNS MADE THIS
DISTURBANCE A STRONG HURRICANE...NO LONGER STRENGTHENS THE CYCLONE.
DUE TO THE UPPER-TROUGH...THE OFFICIAL INTENSITY FORECAST CALLS FOR
SLIGHT INCREASE IN THE WINDS ONLY...WITH THE POTENTIAL FOR SOME
STRENGTHENING AFTER 3 DAYS...WHEN THE UPPER-TROUGH MOVES OUT OF THE
AREA. ALL THIS IS VALID IF THE DEPRESSION SURVIVES THE NEXT TWO
DAYS.

THE DEPRESSION IS IN THE FORMATIVE STAGE SO THE INITIAL MOTION IS
HIGHLY UNCERTAIN. BEST ESTIMATE IS TOWARD THE NORTHWEST OF 315
DEGREES AT 8 KNOTS. THE CURRENT SLOW MOTION SUGGESTS THAT THE
STEERING CURRENTS ARE WEAK. MOST OF THE GLOBAL MODELS FORECAST THE
DEVELOPMENT OF A RIDGE TO THE NORTHEAST OF THE DEPRESSION. THIS
PATTERN WOULD STEER THE CYCLONE TOWARD THE NORTHWEST FOR THE NEXT 2
TO 3 DAYS WITH A POSSIBILITY OF A TURN TO THE WEST-NORTHWEST
THERAFTER...AS A WEAK RIDGE DEVELOPS TO THE NORTH OF THE CYCLONE.
THIS IS CONSISTENT WITH THE GFS...GFDL AND THE ECMWF MODELS.  ON
THIS TRACK...THE CYCLONE SHOULD PASS WELL NORTH OF THE LESSER
ANTILLES.

THE DEPRESSION IS EXPECTED TO PASS NEAR THE NOAA BUOY 41041. THE
DATA FROM THE BUOY WILL GIVE US A BETTER STRUCTURE OF THE CYCLONE
OR IF EXISTS AT ALL.

FORECASTER AVILA

FORECAST POSITIONS AND MAX WINDS

INITIAL      13/2100Z 14.3N  44.9W    30 KT
 12HR VT     14/0600Z 15.0N  46.0W    35 KT
 24HR VT     14/1800Z 16.5N  47.0W    35 KT
 36HR VT     15/0600Z 17.5N  48.0W    35 KT
 48HR VT     15/1800Z 18.5N  49.0W    35 KT
 72HR VT     16/1800Z 20.5N  52.5W    40 KT
 96HR VT     17/1800Z 22.5N  55.5W    45 KT
120HR VT     18/1800Z 24.0N  59.5W    50 KT


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