000
WTPZ43 KNHC 060233
TCDEP3

HURRICANE BLAS DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP032016
800 PM PDT TUE JUL 05 2016

Blas continues to intensify.  Satellite images indicate that Blas
has a typical appearance of a major hurricane with a distinct eye
surrounded by a fairly symmetric ring of deep convection.  The
Dvorak CI-numbers at 0000 UTC were 6.0/115 kt from TAFB and SAB, and
recent ADT values from CIMSS at the University of Wisconsin are a
little higher.  Based on these estimates and the continued
improvement in organization since the time of the classifications,
the initial wind speed is set at 120 kt.  This makes Blas a category
4 hurricane on the Saffir-Simpson Hurricane Wind Scale.

The hurricane has slowed a little in forward speed, and the
latest initial motion estimate is 275/11 kt.  The models are in
very good agreement for the next 3 days or so in showing Blas
continuing westward to west-northwestward on the southwest side of a
mid-level ridge centered over Mexico and the eastern Pacific Ocean.
After that time, however, the model solutions diverge with the bulk
of the guidance showing a northwestward motion due to the cyclone
interacting with a cut-off low northeast of the Hawaiian Islands.
The ECMWF model has a notably different solution showing little
involvement with the cut-off low, which results in Blas continuing
westward. No significant changes were made to the previous
prediction and this track forecast lies close to a consensus of the
GFS and ECMWF models. It should be noted that there is low
confidence at the latter forecast points.

Blas still has another 12-18 hours of favorable conditions for
strengthening.  Beyond that time, the cyclone is expected to move
over cool water and into a progressively drier air mass.  These
conditions should end the strengthening phase and cause a steady
weakening trend.  The official NHC intensity forecast lies at the
upper end the guidance in the short term, but then falls in line
with the intensity model consensus from 36-120 h.

FORECAST POSITIONS AND MAX WINDS

INIT  06/0300Z 14.4N 121.7W  120 KT 140 MPH
 12H  06/1200Z 14.8N 123.4W  130 KT 150 MPH
 24H  07/0000Z 15.4N 125.5W  120 KT 140 MPH
 36H  07/1200Z 16.0N 127.4W  100 KT 115 MPH
 48H  08/0000Z 16.6N 129.0W   85 KT 100 MPH
 72H  09/0000Z 18.2N 132.1W   65 KT  75 MPH
 96H  10/0000Z 20.2N 135.7W   45 KT  50 MPH
120H  11/0000Z 21.6N 139.8W   30 KT  35 MPH...POST-TROP/REMNT LOW

$$
Forecaster Cangialosi