000
WTPZ43 KNHC 192036
TCDEP3
TROPICAL STORM BLAS DISCUSSION NUMBER  10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP032010
200 PM PDT SAT JUN 19 2010
 
A SERIES OF MICROWAVE IMAGES FROM AMSU...SSMIS...SSM/I...AND WINDSAT
SUGGEST THAT THE LOW-LEVEL CENTER OF BLAS REMAINS DISPLACED TO THE
NORTHEAST OF THE DEEP CONVECTION.  THIS IS CONSISTENT WITH THE SHIPS
MODEL AND UW-CIMSS SATELLITE ANALYSIS THAT BOTH INDICATE ABOUT 10
KT OF NORTHEASTERLY TO EASTERLY SHEAR OVER BLAS.  ALSO...THE
CYCLONE APPEARS TO BE INGESTING DRIER AND MORE STABLE AIR INTO THE
NORTHERN SIDE OF THE CIRCULATION...WHICH HAS LIKELY CONTRIBUTED TO
THE THINNING OF THE CLOUD SHIELD NORTH OF THE CENTER.  WHILE THE
COVERAGE AND INTENSITY OF THE DEEP CONVECTION HAVE DECREASED A
LITTLE SINCE EARLIER TODAY...DVORAK FINAL T-NUMBERS REMAIN 3.5 FROM
BOTH TAFB AND SAB...AND THE INTENSITY IS HELD AT 55 KT FOR THIS
ADVISORY.
 
MOST OF THE GUIDANCE SUGGESTS THAT BLAS HAS PEAKED IN INTENSITY. 
THE CYCLONE WILL BE MOVING INTO PROGRESSIVELY COOLER WATERS AND A
DRIER AND MORE STABLE ATMOSPHERIC ENVIRONMENT DURING THE PERIOD...
ESPECIALLY AFTER 48 HOURS.  THE OFFICIAL FORECAST SHOWS A SLOW
WEAKENING BEGINNING AFTER 12 HOURS AND IS IN BEST AGREEMENT WITH
THE LGEM.  BLAS SHOULD WEAKEN TO A REMNANT LOW BY THE END OF THE
PERIOD.
 
VISIBLE IMAGERY AND THE ABOVE-MENTIONED MICROWAVE PASSES LEND A
LITTLE MORE CONFIDENCE TO BOTH THE INITIAL POSITION ESTIMATE AND THE
INITIAL MOTION ESTIMATE OF 280/07.  BLAS IS EXPECTED TO CONTINUE
MOVING WESTWARD SOUTH OF A DEEP-LAYER RIDGE THROUGH ABOUT 48 HOURS.
AFTER THAT TIME...AS THE CYCLONE WEAKENS...BLAS WILL BE STEERED A
LITTLE SOUTH OF DUE WEST BY THE LOW-LEVEL FLOW.  THE NEW OFFICIAL
FORECAST IS A LITTLE NORTH OF THE PREVIOUS ONE DUE TO THE INITIAL
POSITION OF THE CYCLONE BEING FARTHER NORTH...AND REPRESENTS A
BLEND OF THE PREVIOUS FORECAST AND THE MULTI-MODEL CONSENSUS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      19/2100Z 16.7N 110.5W    55 KT
 12HR VT     20/0600Z 16.9N 111.8W    55 KT
 24HR VT     20/1800Z 17.1N 113.8W    50 KT
 36HR VT     21/0600Z 17.3N 115.7W    45 KT
 48HR VT     21/1800Z 17.3N 117.7W    40 KT
 72HR VT     22/1800Z 17.0N 121.5W    35 KT
 96HR VT     23/1800Z 16.5N 125.5W    25 KT...POST-TROP/REMNT LOW
120HR VT     24/1800Z 16.0N 129.0W    20 KT...POST-TROP/REMNT LOW
 
$$
FORECASTER BRENNAN