WTPZ43 KNHC 031439 RRA

TCDEP3



TROPICAL STORM BLAS DISCUSSION NUMBER   3

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP032016

900 AM MDT SUN JUL 03 2016



SATELLITE IMAGERY INDICATES A MARKED INCREASE IN ORGANIZATION OF THE

BLAS' CLOUD PATTERN OVERNIGHT, SUGGESTING THAT THE CYCLONE IS

QUICKLY INTENSIFYING.  THE CENTER IS LOCATED UNDERNEATH A BALL OF

DEEP CONVECTION, THE LATTER WHICH APPEARS TO BE A FORMATIVE CENTRAL

DENSE OVERCAST.  THE LARGE-ENVELOPE CYCLONE ALSO HAS A LENGTHENING

BAND THAT CONSISTS OF VERY COLD-TOPPED CONVECTION IN THE SHAPE OF A

FIGURE SIX. SATELLITE CLASSIFICATIONS ARE T3.0/45 KT AND T3.5/55 KT

FROM SAB AND TAFB AT 1200 UTC, RESPECTIVELY.  THE INITIAL INTENSITY

IS RAISED TO 50 KT, BASED ON A BLEND OF THE TWO INTENSITY ESTIMATES.



THE INITIAL MOTION ESTIMATE IS 285/11.  BLAS IS FORECAST TO MOVE

ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE

CENTERED OVER NORTHERN MEXICO THROUGHOUT THE FORECAST PERIOD, WHICH

SHOULD KEEP THE CYCLONE ON A GENERAL WEST-NORTHWESTERLY COURSE.  THE

MODEL GUIDANCE IS IN VERY GOOD AGREEMENT THROUGH 72 HOURS, BUT

DIVERGES AFTER THAT TIME.  THE GFS AND ITS ENSEMBLE MEAN LIE NEAR

THE PREVIOUS FORECAST AND IS ON THE NORTHERN SIDE OF THE GUIDANCE

ENVELOPE, WHILE THE ECMWF AND ITS ENSEMBLE MEAN ARE MUCH FARTHER

SOUTH.  THE DIFFERENCES BETWEEN THE TWO MODELS APPEAR RELATED TO

SUBTLE VARIATIONS IN THE STRENGTH AND POSITION OF THE SUBTROPICAL

RIDGE FORECAST AFTER DAY 3.  THE NHC TRACK FORECAST IS ADJUSTED A

BIT SOUTH OF THE PREVIOUS ONE, ON THE SOUTHERN SIDE OF THE GUIDANCE

ENVELOPE THROUGH 72 HOURS AND NEAR THE MULTI-MODEL CONSENSUS AFTER

THAT TIME.=