000
WTPZ43 KNHC 072038
TCDEP3

HURRICANE BLAS DISCUSSION NUMBER  20
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP032016
200 PM PDT THU JUL 07 2016

The eye of Blas has become cloud filled in visible satellite imagery
today, but the convective ring surrounding the center has changed
little since this morning.  Recent microwave imagery indicates that
the southwestern portion of the eyewall has eroded somewhat.
Although the subjective Dvorak current intensity estimates have not
changed much since 1200 UTC, the objective T-numbers have decreased
and the initial wind speed has been reduced to 100 kt.  Blas will be
moving over cooler water and into a more stable environment during
the next several days.  This should result in a faster rate of
weakening and Blas is forecast to weaken to a tropical storm in
about 36 hours, and become post-tropical in about 72 hours.  The
updated NHC intensity forecast is between the SHIPS/LGEM guidance
and close to the multi-model intensity consensus.

Blas continues to move west-northwestward or 290/9.  The track
forecast reasoning remains unchanged.  The hurricane is expected to
turn northwestward on Friday between a mid-level ridge over northern
Mexico and a mid- to upper-level low to the northeast of the
Hawaiian Islands.  In 2 to 3 days, a weaker and more shallow Blas
should turn westward in the low-level easterly flow.  The GFS and
ECMWF continue to converge on this solution, and the updated NHC
track is near a consensus of those models.


FORECAST POSITIONS AND MAX WINDS

INIT  07/2100Z 16.6N 127.8W  100 KT 115 MPH
 12H  08/0600Z 17.1N 128.9W   90 KT 105 MPH
 24H  08/1800Z 18.2N 130.3W   75 KT  85 MPH
 36H  09/0600Z 19.5N 131.6W   60 KT  70 MPH
 48H  09/1800Z 20.9N 132.9W   45 KT  50 MPH
 72H  10/1800Z 22.2N 136.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  11/1800Z 22.2N 140.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  12/1800Z 21.8N 145.0W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Brown