000
WTPZ43 KNHC 210238
TCDEP3
TROPICAL DEPRESSION BLAS DISCUSSION NUMBER  15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP032010
800 PM PDT SUN JUN 20 2010
 
SOME DEEP CONVECTION HAS REDEVELOPED THIS EVENING IN ASSOCIATION
WITH TROPICAL DEPRESSION BLAS.  HOWEVER...THE CONVECTION IS LIMITED
IN EXTENT AND IS DISPLACED ABOUT A DEGREE SOUTHWEST OF THE SYSTEM'S
CENTER DUE TO MODERATE NORTHEASTERLY VERTICAL SHEAR.  DVORAK
CI-NUMBERS FROM TAFB AND SAB REMAIN UNCHANGED AND THUS THE INITIAL
INTENSITY IS KEPT AT 30 KT.  THE ENHANCED CONVECTION THIS EVENING
MAY BE THE CYCLONE'S LAST GASP DURING THE DIURNAL CONVECTIVE
MAXIMUM AS THE SSTS ALONG THE TRACK SHOULD BECOME INCREASINGLY
COLDER WHILE THE ATMOSPHERE BECOMES MORE STABLE.  BLAS IS PREDICTED
TO BECOME A REMNANT LOW BY TUESDAY...BUT COULD OCCUR SOONER IF THE
CONVECTION DIES OFF TOMORROW MORNING.  THE INTENSITY FORECAST IS
BASED ON THE INTENSITY MODEL CONSENSUS AND IS UNCHANGED FROM THE
PREVIOUS ADVISORY.

CURRENT MOTION IS 280/12...PRIMARILY DUE TO THE INFLUENCE OF A
NARROW DEEP-LAYER RIDGE NORTH OF BLAS.  WHILE A SUBSTANTIAL
SHORT-WAVE TROUGH WEST OF CALIFORNIA AND A CORRESPONDING BREAK IN
THE RIDGE IS ANTICIPATED TO OCCUR IN A COUPLE OF DAYS...THE
WEAKENING SYSTEM SHOULD BE STEERED BY THE LOW-LEVEL FLOW BY THEN. 
THE FORECAST IS A BLEND OF THE GLOBAL AND HWRF MODELS AND IS VERY
SIMILAR TO THE PREVIOUS OFFICIAL FORECAST.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      21/0300Z 17.9N 116.0W    30 KT
 12HR VT     21/1200Z 18.1N 117.7W    25 KT
 24HR VT     22/0000Z 18.1N 119.7W    25 KT
 36HR VT     22/1200Z 18.0N 121.9W    20 KT...POST-TROP/REMNT LOW
 48HR VT     23/0000Z 17.5N 124.3W    20 KT...POST-TROP/REMNT LOW
 72HR VT     24/0000Z...DISSIPATED
 
$$
FORECASTER LANDSEA/STEWART