WTPZ43 KNHC 061442 RRA

TCDEP3



HURRICANE BLAS DISCUSSION NUMBER  15

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP032016

800 AM PDT WED JUL 06 2016



THE OVERALL SATELLITE APPEARANCE OF BLAS HAS CHANGED LITTLE SINCE

EARLY THIS MORNING.  BLAS HAS CHARACTERISTICS OF AN ANNULAR

HURRICANE WITH A LARGE 25 TO 30 N MI WIDE EYE SURROUNDED BY A

SYMMETRIC CONVECTIVE RING WITH LITTLE OUTER BANDING FEATURES.  THE

INITIAL INTENSITY REMAINS 110 KT, AND IS A BLEND OF THE VARIOUS

OBJECTIVE AND SUBJECTIVE DVORAK SATELLITE INTENSITY ESTIMATES.

BLAS IS CURRENTLY IN A LOW SHEAR ENVIRONMENT AND OVER SSTS OF 27-28

DEGREES CELSIUS.  ALTHOUGH THE SHEAR IS FORECAST TO REMAIN LOW FOR

THE NEXT SEVERAL DAYS, DECREASING SEA SURFACE TEMPERATURES ALONG THE

FORECAST TRACK SHOULD RESULT IN GRADUAL WEAKENING OF THE HURRICANE

DURING THE NEXT 24 TO 36 HOURS.  AFTER THAT TIME, BLAS WILL BE

MOVING OVER SSTS BELOW 26C WHICH SHOULD CAUSE A FASTER RATE OF

WEAKENING, AND THE CYCLONE IS FORECAST TO BECOME POST-TROPICAL IN

ABOUT 4 DAYS.  THE NHC INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS

ADVISORY AND LIES BETWEEN THE SHIPS AND LGEM MODELS.



BLAS IS MOVING WEST-NORTHWESTWARD OR 285 DEGREES AT 10 KT, AND

SHOULD CONTINUE ON THIS GENERAL MOTION DURING THE NEXT 36 TO 48

HOURS WHILE IT MOVES AROUND THE SOUTHWESTERN PORTION OF A MID-LEVEL

RIDGE OVER NORTHERN MEXICO.  BY 72 HOURS, THE MODEL GUIDANCE BEGINS

TO DIVERGE WITH THE GFS, HWRF, GFDL, AND GFS ENSEMBLE MEAN TAKING

BLAS NORTHWESTWARD AROUND THE EASTERN PORTION OF A LARGE MID- TO

UPPER-LEVEL LOW TO THE NORTHEAST OF HAWAII.  THE ECMWF AND UKMET

MODELS SHOW A MORE WESTWARD TRACK, WITH LESS INTERACTION BETWEEN THE=