678 
 WTPZ44 KNHC 220232
 TCDEP4
 
 Hurricane Willa Discussion Number   8
 NWS National Hurricane Center Miami FL       EP242018
 900 PM MDT Sun Oct 21 2018
 
 Willa has continued to rapidly intensify this evening.  Satellite
 images show a well-defined circular eye with a surrounding ring of
 cold cloud tops that are near -80 deg C over the southeastern
 quadrant.  The initial intensity is set to 125 kt, which is near the
 latest Dvorak ADT estimates from CIMSS at the University of
 Wisconsin.  Willa has strengthened at an incredible rate since
 genesis, intensifying from a tropical depression to a category 4
 hurricane in less than 48 hours.
 
 Willa is gradually turning toward the right, with the initial motion
 estimated to be 340/6 kt.  The hurricane is expected to turn
 northward on Monday as it moves around the western periphery of a
 mid-level ridge to the east, followed by a faster northeastward
 motion Monday night and Tuesday when a shortwave trough approaches
 the system.  The models are in fairly good agreement, and only small
 changes were made to the previous NHC track forecast.  On the
 forecast track, Willa is expected to move over Las Islas Marias on
 Tuesday and then move inland over southwestern and west-central
 Mexico Tuesday night or early Wednesday.
 
 The hurricane has certainty taken advantage of the near ideal
 environmental conditions and since these conditions will persist a
 little longer, some additional strengthening is shown in the short
 term.  However, some fluctuations in intensity could occur due to
 eyewall replacement cycles.  The models then show a gradual increase
 in shear and a decrease in available moisture around 24 hours, and
 these factors should cause a slow weakening trend. Regardless,
 Willa is forecast to remain a dangerous hurricane, bringing multiple
 life-threatening hazards to the coast of Mexico. Rapid weakening is
 forecast after the system moves inland and interacts with the
 mountainous terrain.  The NHC intensity forecast lies near the high
 end of the model guidance through dissipation.
 
 Key Messages:
 
 1. Willa is forecast to be a dangerous hurricane when it reaches the
 Islas Marias and the coast of southwestern Mexico by late Tuesday or
 Wednesday bringing a life-threatening storm surge and flash flooding
 along with damaging hurricane-force winds. A Hurricane Warning is
 in effect for these areas, and residents should rush preparations to
 completion to protect life and property and follow any advice given
 by local officials.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  22/0300Z 17.7N 107.2W  125 KT 145 MPH
  12H  22/1200Z 18.6N 107.4W  135 KT 155 MPH
  24H  23/0000Z 19.7N 107.5W  125 KT 145 MPH
  36H  23/1200Z 20.7N 107.2W  115 KT 130 MPH
  48H  24/0000Z 22.1N 106.2W  100 KT 115 MPH
  72H  25/0000Z 26.2N 101.3W   30 KT  35 MPH...POST-TROP/INLAND
  96H  26/0000Z...DISSIPATED
 
 $$
 Forecaster Cangialosi