Tropical Storm LARRY

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TROPICAL STORM LARRY DISCUSSION NUMBER  12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT SAT OCT 04 2003
 
VISIBLE AND INFRARED SATELLITE IMAGERY INDICATE THAT LARRY HAS
CHANGED LITTLE DURING THE PAST 6 HOURS...ALTHOUGH A BURST OF DEEP
CONVECTION HAS DEVELOPED OVER OR NEAR THE LOW-LEVEL CENTER DURING
THE PAST 3 HOURS. SINCE THE CENTER IS BELIEVED TO BE LOCATED NEAR
OR JUST NORTH OF THE COLDEST OVERSHOOTING TOOPS...BASED ON
CONTINUITY WITH THE PREVIOUS RECON FIX AND PAST MOTION...THE
INTENSITY IS BEING MAINTAINED AT 50 KT. 

THE INITIAL MOTION ESTIMATE IS 135/02...BASED ON A 12-HOUR TREND.
LARRY IS EAST AND SOUTH OF AN EAST-WEST ORIENTED MID-LEVEL RIDGE
THAT EXTENDS FROM THE WESTERN GULF OF MEXICO WESTWARD ACROSS
NORTHERN MEXICO. AS THE STRONG MID-LATITUDE TROUGH OVER THE GREAT
LAKES AND SOUTHEASTERN U.S. CONTINUES TO DIG SOUTHEASTWARD...THE
RIDGE TO THE WEST IS FORECAST BY ALL THE GLOBAL MODELS TO BECOME
HIGHLY AMPLIFIED AND SHIFT SLOWLY EASTWARD. THIS SHOULD CAUSE THE
MID-LEVEL STEERING FLOW TO GRADUALLY VEER AROUND AND BECOMING MORE
NORTHERLY...ALBEIT STILL RATHER WEAK. THIS SHOULD CAUSE LARRY TO
GRADUALLY TURN MORE SOUTHWARD AND MOVE INTO THE ISTHMUS OF
TEHUANTEPEC REGION OF SOUTHEASTERN MEXICO IN 24 TO 36 HOURS.
AFTERWARDS...SOME OF THE MODELS LIKE THE GFDL TAKE THE LOW-LEVEL
CENTER QUICKLY ACROSS MEXICO INTO THE NORTHEAST PACIFIC...WHILE THE
REMAINING MODELS LIKE THE GFS AND NOGAPS WEAKEN/DISSIPATE LARRY
OVER MEXICO AND RE-GENERATE A NEW SURFACE LOW OVER THE GULF OF
TEHUANTEPEC. THE OFFICIAL FORECAST IS A LITTLE TO LEFT/EAST OF AND
SLIGHTLY FASTER THAN THE PREVIOUS FORECAST...AND MAINLY FOLLOWS THE
MODEL CONSENSUS OF THE MID-LEVEL VORTICITY CENTER TRACK.

THE RECENT BURST OF CONVECTION NEAR/OVER THE LOW-LEVEL CENTER MAY BE
SIGNALING A BRIEF PERIOD OF INTENSIFICATION...NOW THAT THE OUTER
CONVECTIVE BANDING FEATURES HAVE DISSIPATED. SOME SLIGHT
STRENGTHENING IS FORECAST BEFORE LARRY MAKES LANDFALL...AND IT IS 
POSSIBLE THAT THE CYCLONE COULD BRIEFLY BECOME A HURRICANE TONIGHT
OR TOMORROW MORNING.
 
FORECASTER STEWART
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/1500Z 19.3N  93.7W    50 KT
 12HR VT     05/0000Z 19.0N  93.6W    55 KT
 24HR VT     05/1200Z 18.5N  93.6W    60 KT
 36HR VT     06/0000Z 17.9N  93.7W    40 KT...INLAND
 48HR VT     06/1200Z 17.3N  94.0W    30 KT...DISSIPATING INLAND
 72HR VT     07/1200Z 16.5N  94.5W    20 KT...REMNANT LOW INLAND
 96HR VT     08/1200Z 15.5N  95.5W    20 KT...PACIFIC REMNANT LOW
120HR VT     09/1200Z 15.0N  97.0W    20 KT...PACIFIC REMNANT LOW
 
 
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