000 WTPZ43 KNHC 070834 TCDEP3 TROPICAL STORM BLANCA DISCUSSION NUMBER 5 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032009 200 AM PDT TUE JUL 07 2009 THE STRUCTURE OF BLANCA HAS NOT CHANGED MUCH OVER THE PAST SEVERAL HOURS...AS DEEP CONVECTION REMAINS CONFINED TO A SMALL AREA NEAR THE CENTER AND IN A BAND TO THE SOUTHEAST. THE INITIAL INTENSITY IS HELD AT 45 KT BASED ON DVORAK T-NUMBERS OF 3.0 FROM TAFB AND SAB AT 0600 UTC. WHILE BLANCA'S CIRCULATION REMAINS ROBUST...THE OPPORTUNITY FOR SIGNIFICANT INTENSIFICATION HAS LIKELY PASSED. THE SHIPS MODEL SHOWS THAT THE CYCLONE IS NOW LOCATED OVER SSTS LESS THAN 27C...AND IS HEADED FOR SSTS BELOW 25C IN THE NEXT 12 TO 24 HOURS. THE COMBINATION OF COOL WATERS...A MORE STABLE LOWER TROPOSPHERE AND MODERATE EASTERLY WIND SHEAR SHOULD CAUSE BLANCA TO WEAKEN STEADILY AFTER 24 HOURS. THE OFFICIAL INTENSITY FORECAST HAS BEEN ADJUSTED DOWNWARD IN CLOSE AGREEMENT WITH THE ICON CONSENSUS...AND THE CYCLONE IS FORECAST TO BECOME A REMNANT LOW IN ABOUT 3 DAYS. THE SHIPS MODEL AND SEVERAL OF THE GLOBAL MODELS SHOW BLANCA DISSIPATING BY 96 HOURS...AND SO DOES THE OFFICIAL FORECAST. THE INITIAL MOTION IS ESTIMATED TO BE 295/08 BASED ON RECENT SATELLITE IMAGERY. THE TRACK FORECAST REASONING REMAINS UNCHANGED. BLANCA WILL BE STEERED WEST-NORTHWESTWARD SOUTH OF THE MID-LEVEL RIDGE...WITH A REDUCTION IN FORWARD SPEED AFTER 36 HOURS AS BOTH THE CYCLONE AND THE RIDGE WEAKEN. THE OFFICIAL TRACK FORECAST IS VERY CLOSE TO THE PREVIOUS FORECAST THROUGH 24 HOURS. THEREAFTER...THE OFFICIAL FORECAST IS NUDGED TO THE RIGHT OF THE PREVIOUS FORECAST TOWARD THE NEW MULTI-MODEL CONSENSUS...WHICH SHOWS LESS OF A TURN TOWARD THE WEST PRIOR TO DISSIPATION. FORECAST POSITIONS AND MAX WINDS INITIAL 07/0900Z 18.5N 114.5W 45 KT 12HR VT 07/1800Z 19.0N 115.8W 45 KT 24HR VT 08/0600Z 19.7N 117.4W 40 KT 36HR VT 08/1800Z 20.3N 118.9W 35 KT 48HR VT 09/0600Z 20.7N 120.2W 30 KT 72HR VT 10/0600Z 21.5N 122.5W 20 KT...REMNANT LOW 96HR VT 11/0600Z...DISSIPATED $$ FORECASTER BRENNAN