je.st
news
Tropical Storm Willa Forecast Discussion Number 4
2018-10-21 04:32:09| National Hurricane Center (East Pacific)
Issued at 900 PM MDT Sat Oct 20 2018 000 WTPZ44 KNHC 210232 TCDEP4 Tropical Storm Willa Discussion Number 4 NWS National Hurricane Center Miami FL EP242018 900 PM MDT Sat Oct 20 2018 Willa has rapidly intensified since genesis occurred last night, and it is almost a hurricane. Geostationary satellite and microwave images indicate that banding features have become well established in all quadrants and the inner core has continued to organize. There is still no evidence of an eye feature, however. A blend of the latest satellite intensity estimates supports increasing the initial wind speed to 60 kt. The latest satellite fixes indicate that Willa is now moving northwestward at about 5 kt. The storm is expected to gradually turn to the right as it moves around the western periphery of a mid-level ridge. In response, a northwestward motion should continue for another day or so, followed by a turn toward the north on Monday. After that time, a faster north-northeast to northeast motion is expected when a shortwave trough approaches the system. The latest model guidance, except for the UKMET, show Willa making a sharper northward turn and at a faster pace. The NHC track forecast has been adjusted accordingly to be in better agreement with the latest consensus aids. This forecast is again faster than the previous one and shows Willa making landfall over west-central Mexico in 72 to 96 hours. The storm has taken advantage of near ideal environmental conditions of very low wind shear, high levels of moisture, and warm 29 deg C SSTs. These conditions are expected to prevail for another couple of days, and that should allow Willa to continue to strengthen rapidly. In fact, the SHIPS Rapid Intensification (RI) indices show about 90 percent chance of RI continuing during the next 24 hours. Based on this information and the latest model guidance, the NHC intensity forecast shows Willa becoming a major hurricane in a day or so. Some weakening is likely before Willa reaches the coast due to an increase in shear and a decrease in available moisture, but Willa is forecast to be a hurricane when it reaches the coastline. After landfall, rapid weakening is expected due to interaction with the rugged terrain. FORECAST POSITIONS AND MAX WINDS INIT 21/0300Z 15.7N 106.1W 60 KT 70 MPH 12H 21/1200Z 16.1N 106.6W 80 KT 90 MPH 24H 22/0000Z 16.9N 107.1W 95 KT 110 MPH 36H 22/1200Z 17.7N 107.5W 110 KT 125 MPH 48H 23/0000Z 18.7N 107.8W 110 KT 125 MPH 72H 24/0000Z 20.7N 107.3W 90 KT 105 MPH 96H 25/0000Z 24.1N 104.2W 35 KT 40 MPH...INLAND 120H 26/0000Z...DISSIPATED $$ Forecaster Cangialosi
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics