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Tropical Storm HUMBERTO (Text)

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TROPICAL STORM HUMBERTO DISCUSSION NUMBER  33
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092013
1100 AM AST WED SEP 18 2013

HUMBERRTO APPEARS DISORGANIZED IN SATELLITE IMAGERY THIS MORNING. 
THE MOST CONCENTRATED CONVECTION IS IN BANDS LOCATED ABOUT 150 N MI
EAST OF THE CENTER...WITH ONLY WIDELY SCATTERED CONVECTIVE CELLS
NEAR THE CENTER.  IN ADDITION...THE LOW-LEVEL CIRCULATION IS
BECOMING ELONGATED FROM NORTH-NORTHWEST TO SOUTH-SOUTHEAST.  WATER
VAPOR AND AIRMASS IMAGERY SUGGESTS THE LOW-LEVEL CENTER IS STILL
CLOSE TO AN UPPER-LEVEL LOW...WHICH MAY BE HINDERING THE CENTRAL
CONVECTION.  WHILE DVORAK SATELLITE ESTIMATES ARE BELOW TROPICAL
STORM STRENGTH...AMSU-BASED INTENSITY ESTIMATES DURING THE NIGHT
SUGGEST THE CYCLONE IS STILL A TROPICAL STORM.  THE INITIAL
INTENSITY IS THUS HELD...PERHAPS GENEROUSLY..AT 35 KT.

VISIBLE IMAGERY HAS MADE IT EASIER TO FIND THE CENTER...WHICH IS A
LITTLE FARTHER SOUTH THAN PREVIOUSLY ESTIMATED.  THE INITIAL MOTION
IS NOW 335/4.  HUMBERTO IS EXPECTED TO TURN NORTHWARD DURING THE
NEXT 12 HOURS OR SO...FOLLOWED BY AN ACCELERATION TOWARD THE
NORTH-NORTHEAST AS THE CYCLONE ENTERS THE WESTERLIES.  THE SPREAD
OF THE TRACK MODEL GUIDANCE REMAINS FAIRLY NARROW...AND THE NEW
TRACK FORECAST IS SIMILAR TO THE PREVIOUS FORECAST.

THERE IS STILL TIME FOR HUMBERTO TO STRENGTHEN SOME AS IT MOVES INTO
A MORE FAVORABLE UPPER-LEVEL WIND ENVIRONMENT NORTH OF THE
UPPER-LEVEL LOW.  HOWEVER...BY 48 HOURS THE CYCLONE SHOULD UNDERGO
EXTRATROPICAL TRANSITION AS IT MERGES WITH A FRONTAL SYSTEM.  THE
NEW INTENSITY FORECAST IS THE SAME AS THE PREVIOUS FORECAST...
CALLING FOR HUMBERTO TO BE A STORM-FORCE EXTRATROPICAL LOW BY 72
HOURS...AND THEN BE ABSORBED INTO ANOTHER LOW OVER THE NORTHEASTERN
ATLANTIC.  AN ALTERNATIVE SCENARIO...FAVORED BY THE GFS...ECMWF...
AND CANADIAN MODELS...IS THAT LITTLE STRENGTHENING OCCURS AND THAT
HUMBERTO DEGENERATES TO A TROUGH AS IT ENOUCNTERS THE FRONTAL
SYSTEM.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  18/1500Z 31.3N  43.8W   35 KT  40 MPH
 12H  19/0000Z 32.3N  43.8W   35 KT  40 MPH
 24H  19/1200Z 33.8N  43.4W   40 KT  45 MPH
 36H  20/0000Z 36.1N  42.1W   40 KT  45 MPH
 48H  20/1200Z 38.7N  40.0W   45 KT  50 MPH...POST-TROP/EXTRATROP
 72H  21/1200Z 51.0N  27.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
 96H  22/1200Z...ABSORBED
 
$$
FORECASTER BEVEN
 
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