000
WTPZ43 KNHC 080846
TCDEP3

HURRICANE BLAS DISCUSSION NUMBER  22
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP032016
200 AM PDT FRI JUL 08 2016

The eye of Blas is no longer apparent in infrared imagery, but cold
cloud tops persist in a CDO over the center.  The initial intensity
is lowered to 90 kt based on a blend of the latest subjective and
objective Dvorak estimates.  Rapid weakening is expected during the
next 48 hours as Blas moves over much cooler waters and into a drier
and more stable airmass, and the NHC forecast during this time is
close to the latest LGEM guidance.  Blas is expected to become
post-tropical by 48 hours and then continue a slow spin down through
the remainder of the forecast period.

The initial motion estimate is 300/09, as Blas is beginning to gain
some latitude as it moves around the southwestern edge of a
subtropical ridge centered well to the east over Mexico.  The track
model guidance shows Blas turning northwestward between 12 to 36 h
as it moves into a weakness ahead of a large upper-level low
northeast of the Hawaiian Islands.  After that time a weakening Blas
should turn westward and then west-southwestward under the influence
of the low-level trade wind flow.  The new NHC forecast is a bit
north of the previous one through 48 hours following the latest
guidance trend.  Late in the period the guidance has shifted
southward, and the new NHC track is south of the previous one.
This forecast is little south of the latest GFS track and ends up a
bit north of the multi-model consensus by day 5.

The initial and forecast wind radii were adjusted based on a pair
of timely ASCAT-A and ASCAT-B passes over Blas between 0530 and 0630
UTC.

FORECAST POSITIONS AND MAX WINDS

INIT  08/0900Z 17.4N 129.4W   90 KT 105 MPH
 12H  08/1800Z 18.3N 130.3W   75 KT  85 MPH
 24H  09/0600Z 19.7N 131.5W   60 KT  70 MPH
 36H  09/1800Z 21.0N 132.8W   45 KT  50 MPH
 48H  10/0600Z 21.8N 134.4W   35 KT  40 MPH...POST-TROPICAL
 72H  11/0600Z 22.0N 138.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  12/0600Z 21.0N 143.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  13/0600Z 20.0N 147.0W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Brennan