793 
 WTPZ44 KNHC 221515 CCA
 TCDEP4
 
 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