Tropical Storm BLAS
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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
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