283 
WTPZ41 KNHC 022032
TCDEP1

Hurricane Sergio Discussion Number  14
NWS National Hurricane Center Miami FL       EP212018
200 PM PDT Tue Oct 02 2018

Sergio has intensified significantly today.  The eye of the
hurricane has become better defined, and is embedded in very cold
convective cloud tops.  Outer banding features are also well
defined.  Upper-tropospheric outflow is strong over the western and
southern portions of the circulation, and a little restricted to
the northeast.  The advisory intensity is set, probably
conservatively, to 100 kt in agreement with a Dvorak estimate from
SAB.  Only modest northeasterly shear is expected to affect Sergio
over the next few days.  That, along with warm waters and a very
moist middle troposphere, should be conducive for further
strengthening.  The official forecast is near the upper end of the
intensity guidance model suite.

The system continues moving mostly westward, or 280/11 kt.  There
is little change to the track forecast reasoning from the previous
couple of advisory packages.  A mid-level ridge to the north of
Sergio should weaken within the next 12 to 24 hours as a broad
trough drops in from the northwest.  These changes in the steering
flow should cause the hurricane to turn toward the west-northwest by
this evening or tonight, and to begin moving northwestward on
Wednesday.  The official track forecast is is very similar to the
previous one and, again, follows the latest multi-model consensus.

Some slight enlargements to the wind radii were made over the
eastern semicircle of Sergio based on scatterometer data.

FORECAST POSITIONS AND MAX WINDS

INIT  02/2100Z 11.2N 115.1W  100 KT 115 MPH
 12H  03/0600Z 12.0N 116.3W  115 KT 130 MPH
 24H  03/1800Z 13.1N 117.8W  120 KT 140 MPH
 36H  04/0600Z 14.2N 119.1W  120 KT 140 MPH
 48H  04/1800Z 15.2N 120.5W  115 KT 130 MPH
 72H  05/1800Z 16.3N 123.0W   95 KT 110 MPH
 96H  06/1800Z 16.5N 126.0W   90 KT 105 MPH
120H  07/1800Z 16.5N 128.5W   80 KT  90 MPH

$$
Forecaster Pasch