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HURRICANE BLAS DISCUSSION NUMBER  23
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP032016
800 AM PDT FRI JUL 08 2016

Despite being over cool water, the convection associated with
Blas remains deep with cloud tops below -70C. Recent microwave
data show that the eye of Blas is still intact and it has
occasionally been evident in infrared satellite imagery this
morning.  Subjective and objective Dvorak T-numbers are gradually
decreasing and a blend of the latest estimates yields an initial
wind speed of 85 kt.  The hurricane will be moving over waters
below 24C and into a more stable atmospheric environment during the
next 12 to 24 hours.  This is expected to cause rapid weakening and
Blas is forecast to weaken to a tropical storm by early Saturday,
and become post-tropical in about 48 hours.

Blas is still moving west-northwestward or 300/9 kt.  The cyclone is
expected to turn northwestward very soon between a mid-level ridge
extending westward off the coast of Mexico and a mid- to upper-level
low northeast of Hawaii.  As Blas weakens and becomes a more
vertically shallow system, it should turn back westward, then
west-southwestward in the low level trade wind flow in 48 to 72
hours.  The bulk of the track guidance has shifted a bit southward
at 48 hours and beyond, and the NHC forecast has been adjusted in
that direction.  The updated track is near the center of the model
envelope through 72 hours, but is north of the multi-model consensus
after that time out of respect for the GFS, GFS ensemble mean, and
continuity with the previous NHC track.


FORECAST POSITIONS AND MAX WINDS

INIT  08/1500Z 17.8N 130.0W   85 KT 100 MPH
 12H  09/0000Z 19.0N 130.9W   70 KT  80 MPH
 24H  09/1200Z 20.3N 132.2W   55 KT  65 MPH
 36H  10/0000Z 21.3N 133.6W   40 KT  45 MPH
 48H  10/1200Z 21.7N 135.3W   35 KT  40 MPH...POST-TROPICAL
 72H  11/1200Z 21.5N 139.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  12/1200Z 20.3N 144.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  13/1200Z 19.5N 147.5W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Brown

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