920 
WTPZ42 KNHC 040233
TCDEP2

Hurricane Olivia Discussion Number  13
NWS National Hurricane Center Miami FL       EP172018
800 PM PDT Mon Sep 03 2018

Olivia continues to strengthen with convection deepening near the
center, and the latest microwave passes show a nearly complete
eyewall underneath the central dense overcast.  Dvorak estimates
from TAFB/SAB are a consensus 65 kt, and that will be the initial
wind speed.

A bit surprisingly, Olivia has intensified 25 kt over the past 24
hours.  The current northeasterly shear apparently has not been
enough to cause the strengthening rate to decrease, although some
models are still suggesting the shear will disrupt the hurricane
over the next couple of days.  After inspecting the environmental
winds, it appears that most of the shear will avoid the inner core,
so the official forecast is raised from the previous one, lying near
the upper edge of the guidance.  This forecast still feels a bit
conservative, given the explosive nature of many of the 2018
eastern Pacific cyclones.  Olivia should move over more marginal
waters in a few days, and a gradual weakening is indicated at long
range.

A gradual acceleration continues with Olivia, now moving westward
at about 8 kt.  A strengthening ridge over the eastern Pacific
should steer the cyclone westward and west-northwestward at an
increasing forward pace over the next several days.  The model
guidance is tightly packed on this solution, and the latest NHC
track forecast is basically just an update of the previous
prediction.

FORECAST POSITIONS AND MAX WINDS

INIT  04/0300Z 16.8N 116.0W   65 KT  75 MPH
 12H  04/1200Z 16.9N 117.4W   75 KT  85 MPH
 24H  05/0000Z 17.1N 119.5W   85 KT 100 MPH
 36H  05/1200Z 17.4N 121.8W   85 KT 100 MPH
 48H  06/0000Z 18.0N 124.2W   85 KT 100 MPH
 72H  07/0000Z 19.7N 129.7W   75 KT  85 MPH
 96H  08/0000Z 21.5N 135.3W   65 KT  75 MPH
120H  09/0000Z 23.0N 140.5W   55 KT  65 MPH

$$
Forecaster Blake