000 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