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Tropical Storm BLANCA
ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM
TROPICAL DEPRESSION BLANCA DISCUSSION NUMBER 16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2 PM PDT FRI JUN 20 2003
BLANCA HAS SHEARED APART THIS AFTERNOON. SATELLITE IMAGERY
INDICATES THE LOW-LEVEL CENTER HAS BECOME NEARLY STATIONARY...WHILE
THE MID/UPPER-LEVEL CENTER IS MOVING QUICKLY WESTWARD. THERE IS
NOW LITTLE SIGNIFICANT CONVECTION ASSOCIATED WITH THE CYCLONE.
BASED ON THIS AND AN SSM/I OVERPASS AT 1455Z THAT SHOWED AT BEST
30-35 KT WINDS...BLANCA IS DOWNGRADED TO A 30 KT TROPICAL
DEPRESSION.
THE INITIAL MOTION IS SOMEWHERE BETWEEN STATIONARY AND A WESTWARD
DRIFT. THERE IS ONE CHANGE TO THE SYNOPTIC REASONING FROM THE
MORNING PACKAGE. IN ADDITION TO THE WEAK RIDGE NORTH OF
BLANCA...THE CYCLONE IS BECOMING EMBEDDED IN THE WESTERN END OF A
TROUGH ASSOCIATED WITH THE TROPICAL DISTURBANCE NEAR THE GULF OF
TEHAUNTEPEC. VISIBLE IMAGERY SHOWS WESTERLY LOW-LEVEL FLOW JUST
SOUTH OF BLANCA FEEDING INTO THE DISTURBANCE. NHC GUIDANCE...SAVE
THE GFDN...STILL FORECASTS A WESTWARD MOTION...AND THE TRACK
FORECAST WILL BE SIMILAR TO...BUT SLOWER THAN THE PREVIOUS PACKAGE.
HOWEVER...THERE IS AN INCREASING CHANCE THAT BLANCA OR ITS REMNANTS
COULD BE PULLED EASTWARD AND ABSORBED INTO THE DISTURBANCE AS SHOWN
BY THE GFDN.
GIVEN THE TRACK RECORD OF BLANCA...THERE IS STILL A CHANCE FOR
CONVECTIVE FLARE-UPS THAT COULD BRIEFLY CAUSE SOME STRENGTHENING.
HOWEVER...THE OVERALL INTENSITY TREND SHOULD BE DOWN MAINLY DUE
TO SHEAR. THE INTENSITY FORECAST CONTINUES TO CALL FOR GRADUAL
WEAKENING UNTIL DISSIPATION. SHOULD CONVECTION NOT RE-DEVELOP NEAR
THE CENTER...BLANCA COULD WEAKEN FASTER THAN CURRENTLY FORECAST.
FORECASTER BEVEN
FORECAST POSITIONS AND MAX WINDS
INITIAL 20/2100Z 15.5N 106.1W 30 KT
12HR VT 21/0600Z 15.5N 106.5W 30 KT
24HR VT 21/1800Z 15.5N 107.0W 25 KT
36HR VT 22/0600Z 15.6N 107.6W 25 KT...DISSIPATING
48HR VT 22/1800Z 15.8N 108.2W 20 KT...REMNANT LOW
72HR VT 23/1800Z 16.0N 109.0W 20 KT...REMNANT LOW
96HR VT 24/1800Z...DISSIPATED
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