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Hurricane Willa Discussion Number  10...corrected
NWS National Hurricane Center Miami FL       EP242018
900 AM MDT Mon Oct 22 2018

Corrected wording in Key Messages number 2

Willa is an extremely impressive hurricane in infrared and visible
satellite imagery this morning.  The small, but very distinct, eye
is embedded within a symmetric central dense overcast with cloud
tops of -70 to -80 degrees Celsius.  A very recent SSMIS microwave
overpass is the first to indicate that an outer eyewall has formed,
suggesting that an eyewall replacement cycle has started.  The
latest objective T-numbers from UW-CIMSS are T7.0/140 kt, and
subjective Dvorak intensity estimates from TAFB and SAB are 140 kt
and 127 kt, respectively.  Based on these data the initial intensity
has been increased to 140 kt.  An Air Force Reserve Hurricane Hunter
aircraft is currently en route to Wilma and should provide a better
assessment of the storm's intensity by early this afternoon.

Willa is moving northward 6 kt.  The hurricane is forecast to
continue to move northward today around the western flank of a
deep-layer ridge that is located over the Gulf of Mexico.
A short wave trough that is seen in water vapor imagery near 130W
longitude is forecast to deepen as it moves eastward toward Baja
California.  This should cause Willa to turn north-northeastward
tonight, then accelerate northeastward on Tuesday, bringing the
center of the hurricane onshore along the west-central coast of
Mexico Tuesday afternoon or evening.  As mentioned in the previous
advisory, the track guidance is good agreement on the overall
scenario but there are still some notable differences in the
predicted forward speed of the hurricane.  The NHC track forecast
leans toward the faster solutions of the GFS and GFS ensemble
mean, which have been handling Willa's track the best so far.

The environment of low wind shear and water temperatures of 28
to 29.5 degrees Celsius suggest some additional strengthening is
possible but with the evidence that an eyewall replacement has
begun, some fluctuations intensity are possible during the next 12
to 24 hours.  After that time, increasing southwesterly shear is
forecast to induce weakening, but Willa is likely to remain an
extremely dangerous major hurricane when it makes landfall along the
west-central coast of Mexico.  After landfall, shear and the
mountainous terrain of Mexico will cause rapid weakening and
dissipation of the cyclone.

Key Messages:

1. A life-threatening storm surge is expected Tuesday along the
coasts of the Isla Marias, and west-central and southwestern
Mexico near the path of Willa.  Residents should rush preparations
to completion to protect life and property and follow any advice
given by local officials.

2. Everyone in Isla Marias, and within the hurricane warning area
along coast of west-central Mexico should prepare for life-
threatening major hurricane winds associated with the core of
Willa.  Hurricane force winds will also extend inland across the
mountainous areas of west-central Mexico as Willa moves inland.

3. Heavy rainfall from Willa is likely to produce life-threatening
flash flooding and landslides over much of southwestern and
west-central Mexico.


FORECAST POSITIONS AND MAX WINDS

INIT  22/1500Z 19.1N 107.2W  140 KT 160 MPH
 12H  23/0000Z 20.1N 107.2W  140 KT 160 MPH
 24H  23/1200Z 21.4N 106.9W  135 KT 155 MPH
 36H  24/0000Z 23.1N 105.6W   90 KT 105 MPH...INLAND
 48H  24/1200Z 25.4N 102.5W   30 KT  35 MPH...INLAND
 72H  25/1200Z...DISSIPATED

$$
Forecaster Brown

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