000 WTPZ43 KNHC 201002 TCDEP3 TROPICAL STORM BLAS DISCUSSION NUMBER 12...CORRECTED NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP032010 200 AM PDT SUN JUN 20 2010 CORRECTED TO INDICATE 48 HOUR POSITION AS POST-TROP/REMNT LOW INFRARED SATELLITE IMAGES INDICATE THAT LARGE MASS OF DEEP CONVECTION ASSOCIATED WITH BLAS HAS DECREASED CONSIDERABLY IN INTENSITY AND COVERAGE DURING THE PAST SEVERAL HOURS. THE OVERALL CONVECTIVE PATTERN HAS ALSO BECOME LESS SYMMETRIC AND A 0355 UTC TRMM PASS INDICATED THAT THE CENTER WAS SLIGHTLY MORE REMOVED FROM THE CONVECTION THAN IT WAS EARLIER. BASED UPON ITS CURRENT APPEARANCE...THE CURRENT INTENSITY ESTIMATE IS LOWERED TO 40 KT FOR THIS ADVISORY IN AGREEMENT WITH THE LATEST DVORAK INTENSITY ESTIMATE OF FROM TAFB AND WITH RECENT CIMSS AODT VALUES BETWEEN 2.5 AND 3.0. ALTHOUGH THE MODEL GUIDANCE INDICATES THAT THERE SHOULD BE A REDUCTION IN THE VERTICAL WIND SHEAR OVER BLAS DURING THE NEXT 24-48 HOURS...THE CYCLONE IS ALREADY MOVING OVER PROGRESSIVELY LOWER SEA SURFACE TEMPERATURES AND ENCOUNTERING A MORE STABLE ATMOSPHERE. THE ABOVE NEGATIVE FACTORS SHOULD OVERWHELM ANY POSITIVE EFFECT FROM THE LOWER VERTICAL WIND SHEAR AND RESULT IN A CONTINUED STEADY WEAKENING OVER THE NEXT FEW DAYS. THE OFFICIAL FORECAST IS ADJUSTED DOWNWARD FROM THE PREVIOUS ADVISORY BASED UPON CURRENT TRENDS...AND BLAS IS FORECAST TO BECOME REMNANT LOW WITHIN 2 DAYS. THE ABOVE TRMM PASS INDICATES THAT BLAS MAY BE MOVING SLIGHTLY RIGHT OF THE PREVIOUS TRACK...WITH THE INITIAL MOTION ESTIMATE NOW 290/08. MIDDLE- TO UPPER-LEVEL RIDGING EXTENDING FROM THE SOUTH CENTRAL UNITED STATES WEST-SOUTHWESTWARD INTO THE TROPICAL EAST PACIFIC IS EXPECTED TO STEER BLAS ON WEST-NORTHWESTWARD TO WESTWARD COURSE FOR THE NEXT DAY OR TWO. THEREAFTER...AS THE CYCLONE WEAKENS FURTHER AND BECOMES MORE SHALLOW...IT SHOULD BE GUIDED WESTWARD OR WEST-SOUTHWESTWARD BY THE LOW-LEVEL FLOW UNTIL DISSIPATION. THE OFFICIAL FORECAST TRACK IS ADJUSTED SLIGHTLY NORTHWARD TO ACCOUNT FOR THE MORE NORTHWARD INITIAL MOTION. FORECAST POSITIONS AND MAX WINDS INITIAL 20/0900Z 17.5N 112.3W 40 KT 12HR VT 20/1800Z 17.7N 113.7W 35 KT 24HR VT 21/0600Z 18.0N 115.7W 30 KT 36HR VT 21/1800Z 18.1N 117.6W 25 KT 48HR VT 22/0600Z 18.0N 119.6W 20 KT...POST-TROP/REMNT LOW 72HR VT 23/0600Z 17.2N 123.5W 20 KT...POST-TROP/REMNT LOW 96HR VT 24/0600Z...DISSIPATED $$ FORECASTER KIMBERLAIN