000
WTPZ43 KNHC 190845
TCDEP3
TROPICAL STORM BLAS DISCUSSION NUMBER   8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP032010
200 AM PDT SAT JUN 19 2010
 
INFRARED SATELLITE IMAGERY INDICATES THAT BLAS HAS MAINTAINED A
LARGE AREA OF COLD CONVECTIVE TOPS DURING THE PAST SEVERAL HOURS.
HOWEVER...THE CONVECTIVE PATTERN...WITH A SHARP EASTERN EDGE...
APPEARS SOMEWHAT AMORPHOUS AND RESEMBLES THAT OF A SHEARED TROPICAL
CYCLONE. A 0451 UTC TRMM PASS CONFIRMS THAT BLAS CONTINUES TO SUFFER
FROM THE EFFECTS OF NORTHEASTERLY SHEAR...WITH THE LOW-LEVEL CENTER
STILL ON THE NORTHEASTERN EDGE OF THE DEEPEST CONVECTIVE CLOUDS.
GIVEN THAT THERE HAS BEEN NO FURTHER INCREASE IN ORGANIZATION AND
THE TAFB DVORAK INTENSITY ESTIMATE REMAINS AT 3.0/45 KT...THE
INITIAL INTENSITY IS UNCHANGED AT 45 KT.
 
CONVENTIONAL AND MICROWAVE SATELLITE CENTER FIXES YIELD AN INITIAL
MOTION ESTIMATE OF 285/6.  GLOBAL MODELS SHOW A STRONG DEEP LAYER
RIDGE EXTENDING WEST-SOUTHWESTWARD FROM THE SOUTH CENTRAL UNITED
STATES INTO THE TROPICAL EAST PACIFIC WHICH SHOULD STEER BLAS ON A
GENERAL WESTWARD TO WEST-NORTHWESTWARD COURSE THROUGH 36-48
HOURS...WITH A MINOR INCREASE IN FORWARD SPEED. THEREAFTER...BLAS
IS EXPECTED TO BECOME A SHALLOW SYSTEM AND TURN WEST-SOUTHWESTWARD
IN THE LOW-LEVEL FLOW.  THE NEW TRACK FORECAST REPRESENTS A BLEND
OF THE PREVIOUS OFFICIAL TRACK AND THE MULTI-MODEL TVCN CONSENSUS.
 
THE SHIPS MODEL AND UW-CIMSS VERTICAL WIND SHEAR ANALYSES CONTINUE
TO ANALYZE MODERATE NORTHEASTERLY SHEAR OVER THE CYCLONE. HOWEVER...
THE SHIPS MODEL STILL INDICATES A REDUCTION IN THE VERTICAL SHEAR
OVER THE NEXT COUPLE OF DAYS...POSSIBLY A RESULT OF BLAS MOVING OUT
OF THE MONSOONAL ENVIRONMENT IN WHICH IT HAS BEEN EMBEDDED AND INTO
ONE WITH A DEEP LAYER OF EASTERLIES. HOWEVER...BEYOND 24 HOURS BLAS
IS EXPECTED TO REACH COOLER WATER AND ENCOUNTER A MORE STABLE
ATMOSPHERE...THE COMBINATION OF WHICH SHOULD LEAD TO WEAKENING. THE
OFFICIAL INTENSITY FORECAST REPRESENTS AN UPDATE OF THE PREVIOUS
ONE...WITH THE FORECAST CLOSELY FOLLOWING THE LGEM INTENSITY
GUIDANCE.
 
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      19/0900Z 16.4N 109.1W    45 KT
 12HR VT     19/1800Z 16.7N 110.4W    45 KT
 24HR VT     20/0600Z 16.9N 112.1W    40 KT
 36HR VT     20/1800Z 17.0N 114.0W    40 KT
 48HR VT     21/0600Z 17.1N 115.9W    35 KT
 72HR VT     22/0600Z 16.9N 119.5W    30 KT
 96HR VT     23/0600Z 16.5N 123.0W    25 KT...POST-TROP/REMNT LOW
120HR VT     24/0600Z 16.0N 126.5W    20 KT...POST-TROP/REMNT LOW
 
$$
FORECASTER KIMBERLAIN