Tropical Storm MELISSA

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TROPICAL STORM MELISSA DISCUSSION NUMBER   7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL142007
1100 PM EDT SAT SEP 29 2007

VERY DEEP CONVECTION HAS BEEN PERSISTING NEAR MELISSA FOR THE PAST
SEVERAL HOURS...AND THE CENTER APPEARS TO BE JUST SOUTH OF A NEW
BURST OF THUNDERSTORMS.  SATELLITE INTENSITY ESTIMATES ARE
INCREASING A LITTLE...AND THE INITIAL INTENSITY WILL BE NUDGED
UPWARD TO 40 KT.  THIS INTENSIFICATION IS EXPECTED TO BE
SHORT-LIVED AS INCREASING WESTERLY SHEAR AFFECTS THE TROPICAL
CYCLONE.  A SLOW WEAKENING IS SHOWN IN THE NHC FORECAST... AND THEN
IS A LITTLE FASTER AFTER 36 HOURS AS THE SHIPS MODEL DIAGNOSES OVER
30 KT OF DESTRUCTIVE WESTERLY SHEAR.  MELISSA IS A SMALL TROPICAL
CYCLONE...AND SINCE SMALL STORMS ARE TYPICALLY MORE SUSCEPTIBLE TO
SHEAR...IT WOULD NOT BE SURPRISING FOR IT TO DISSIPATE FASTER THAN
SHOWN BELOW.
 
THE STORM APPEARS TO BE MOVING TOWARD THE WEST-NORTHWEST OR
295/8...BUT THERE IS A FAIR AMOUNT OF UNCERTAINTY DUE TO THE CENTER
BEING OBSCURED ON SATELLITE IMAGES.  A BUILDING RIDGE TO THE NORTH
OF MELISSA SHOULD KEEP THE STORM ON THE SAME GENERAL TRACK WITH A
SMALL ACCELERATION.  IF THE SYSTEM INTENSIFIES A BIT...IT MAY
BRIEFLY MOVE A LITTLE TO THE RIGHT...BUT THAT TRACK WOULD TAKE IT
OVER COOLER WATERS MORE QUICKLY.  THE OFFICIAL FORECAST IS BASICALLY
AN UPDATE TO THE PREVIOUS FORECAST...AND IS CLOSE TO A CONSENSUS OF
THE UMKET/GFDL/NOGAPS MODELS.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      30/0300Z 15.8N  30.2W    40 KT
 12HR VT     30/1200Z 16.5N  31.6W    40 KT
 24HR VT     01/0000Z 17.4N  33.7W    35 KT
 36HR VT     01/1200Z 18.4N  35.8W    35 KT
 48HR VT     02/0000Z 19.5N  38.0W    30 KT
 72HR VT     03/0000Z 22.0N  42.0W    25 KT...DISSIPATING
 96HR VT     04/0000Z 24.5N  44.5W    20 KT...REMNANT LOW
120HR VT     05/0000Z...DISSIPATED
 
$$
FORECASTER BLAKE
 
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