Tropical Storm CARLOTTA

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TROPICAL STORM CARLOTTA DISCUSSION NUMBER   4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP042006
200 PM PDT WED JUL 12 2006

THE ORGANIZATION OF THE TROPICAL STORM CONTINUES TO INCREASE...AND
BANDING FEATURES ARE NOW EVIDENT.  CARLOTTA IS A LARGE TROPICAL
CYCLONE THAT CURRENTLY LACKS MUCH OF A CENTRAL DENSE OVERCAST.  THE
CURRENT INTENSITY ESTIMATE OF 50 KT IS A BLEND OF DVORAK
CLASSIFICATION VALUES FROM TAFB...SAB AND AFWA.  A WARM WATER/LOW
VERTICAL SHEAR ENVIRONMENT IS LIKELY TO PREVAIL FOR CARLOTTA OVER
THE NEXT COUPLE OF DAYS.  CONTINUED INTENSIFICATION IS
PREDICTED...IN LINE WITH THE CONSENSUS OF THE NUMERICAL INTENSITY
FORECAST GUIDANCE...THE SO-CALLED ICON.  BY THE END OF THE FORECAST
PERIOD I EXPECT CARLOTTA TO BE TRAVERSING SUBSTANTIALLY COOLER
WATERS...AND TO BE WEAKENING RATHER RAPIDLY.

THE CENTER IS EASIER TO LOCATE ON VISIBLE IMAGES...NONETHELESS THE
INITIAL MOTION ESTIMATE IS ABOUT THE SAME AS BEFORE...290/12.  A
MID-LEVEL SUBTROPICAL RIDGE TO THE NORTH OF CARLOTTA...WITH ITS
AXIS ALONG 30N-35N...SHOULD PROVIDE A WEST-NORTHWESTWARD STEERING
REGIME FOR THE NEXT FEW DAYS.  SOME OF THE DYNAMICAL MODEL GUIDANCE
APPEARS UNREALISTIC.  IN PARTICULAR...THE LATEST U.K. MET. OFFICE
GLOBAL MODEL INTEGRATION DEPICTS A DECOUPLING OF CARLOTTA BEGINNING
IN ABOUT 24 HOURS...WITH THE 500 MB CENTER MOVING OFF TO THE WEST
AND LEAVING THE SURFACE CENTER MEANDERING AND WEAKENING NEAR 110W
LONGITUDE.  THIS SCENARIO APPEARS UNREALISTIC FOR SUCH A LARGE
DEVELOPING CYCLONE...AND SO THE U.K. MODEL IS DISREGARDED FOR THIS
PACKAGE.
.
WIND RADII HAVE BEEN EXPANDED BASED ON AN EARLIER QUIKSCAT PASS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      12/2100Z 15.3N 106.4W    50 KT
 12HR VT     13/0600Z 15.8N 108.0W    60 KT
 24HR VT     13/1800Z 16.3N 110.0W    75 KT
 36HR VT     14/0600Z 16.7N 112.0W    80 KT
 48HR VT     14/1800Z 17.0N 114.0W    80 KT
 72HR VT     15/1800Z 17.5N 117.0W    70 KT
 96HR VT     16/1800Z 18.0N 119.5W    50 KT
120HR VT     17/1800Z 19.0N 122.0W    30 KT
 
$$
FORECASTER PASCH
 
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