000
WTPZ43 KNHC 180833
TCDEP3
TROPICAL STORM BLAS DISCUSSION NUMBER   4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP032010
200 AM PDT FRI JUN 18 2010
 
THE CLOUD PATTERN HAS DETERIORATED DURING THE PAST FEW HOURS AND
MICROWAVE DATA SHOW THAT THE CENTER IS STILL WELL REMOVED TO THE
NORTHEAST OF THE LIMITED CONVECTION. SINCE DVORAK T-NUMBERS HAVE
DECREASED...THE INITIAL INTENSITY HAS BEEN ADJUSTED DOWN TO 35
KNOTS.  IN FACT...A RECENT ASCT PASS SHOWS MAXIMUM WINDS OF ONLY 30
KNOTS.  THE OFFICIAL FORECAST CALLS FOR NO CHANGE IN STRENGTH
DURING THE NEXT 2 DAYS AND A GRADUAL WEAKENING THEREAFTER. BLAS
COULD WEAKEN FASTER THAN INDICATED SINCE IT SEEMS THAT STABLE AIR
IS ALREADY AFFECTING THE CIRCULATION...AND THE CYCLONE IS NEAR
COOLER WATERS.  NONE OF THE LATEST GUIDANCE SHOWS INTENSIFICATION.   

BLAS IS MOVING TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 4 KNOTS
EMBEDDED WITHIN WEAK STEERING CURRENTS. MOST OF THE GLOBAL MODELS
BUILD A RIDGE TO THE NORTH OF THE CYCLONE...A PATTERN WHICH FAVORS A
WEST-NORTHWEST TO WEST MOTION WITH A SLIGHT INCREASE IN FORWARD
SPEED.  BECAUSE BLAS IS EXPECTED TO WEAKEN...IT MOST LIKELY BE
STEERED WESTWARD BY THE LOW LEVEL FLOW.  

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      18/0900Z 15.8N 106.7W    35 KT
 12HR VT     18/1800Z 16.0N 107.2W    35 KT
 24HR VT     19/0600Z 16.3N 108.0W    35 KT
 36HR VT     19/1800Z 16.7N 109.5W    35 KT
 48HR VT     20/0600Z 17.0N 111.0W    35 KT
 72HR VT     21/0600Z 17.0N 114.0W    30 KT
 96HR VT     22/0600Z 17.0N 117.0W    25 KT
120HR VT     23/0600Z 16.5N 120.5W    20 KT...POST-TROP/REMNT LOW
 
$$
FORECASTER AVILA