000 WTPZ44 KNHC 220846 TCDEP4 Hurricane Roslyn Discussion Number 10 NWS National Hurricane Center Miami FL EP192022 300 AM MDT Sat Oct 22 2022 Roslyn has intensified rapidly during the past 24 hours. A well-defined eye has formed in infrared satellite imagery since the time of the previous advisory, with cloud tops in the surrounding central dense overcast (CDO) as cold as -80 degrees Celsius. The satellite presentation has improved significantly enough to yield Dvorak data-T numbers of 5.5 (102 kt) from TAFB and SAB at 06 UTC. Since Roslyn's structure has improved a bit since that time, the initial intensity is set at 105 kt. The initial motion is now northwestward, or 315/6 kt. Roslyn is expected to continue recurving around the western periphery of a mid-level high centered over Mexico during the next 36 hours. The bulk of the track models indicate that the hurricane will pass just offshore of Cabo Corrientes, Mexico, by tonight, and then accelerate north-northeastward on Sunday, likely making landfall on the coast of the Mexican state of Nayarit. After landfall, Roslyn's remnants are expected to accelerate toward the northeast over northern Mexico. The updated NHC track forecast shows a slightly wider recurvature than the previous forecast during the first 24 hours, following the tightly clustered model solutions, but the expected landfall ends up in the same general location as before. Roslyn has roughly another 12 hours before deep-layer southwesterly shear increases to moderate levels. But before that happens, the environment appears conducive for additional strengthening, possibly still at a rapid rate. SHIPS Rapid Intensification indices indicate there is a 50/50 chance of a 20-kt increase in winds over the next 12 hours, and given the short-term satellite trends, the NHC intensity forecast now shows Roslyn reaching category 4 intensity later today. The increase in shear should induce some weakening in the last few hours while Roslyn approaches the coast of Mexico, but the storm could still be at or near major hurricane strength around the time of landfall on Sunday. After landfall, the 5000- to 8000-ft mountains of the Sierra Madre Occidentals are expected to significantly disrupt Rosalyn's circulation, and even though a remnant low is shown in the forecast over the Mexican Plateau at 48 hours, it's likely that Rosalyn will have dissipated by that time. Key Messages: 1. Roslyn is forecast to be near or at major hurricane strength when it passes near and makes landfall along the west-central coast of Mexico Saturday night and Sunday, accompanied by damaging winds and a dangerous storm surge. Preparations within the Hurricane Warning area along the west-central coast of Mexico should be rushed to completion. 2. Heavy rainfall could lead to flash flooding and possible landslides in areas of rugged terrain over coastal southwestern and west-central Mexico. FORECAST POSITIONS AND MAX WINDS INIT 22/0900Z 17.3N 106.1W 105 KT 120 MPH 12H 22/1800Z 18.3N 106.4W 120 KT 140 MPH 24H 23/0600Z 20.1N 106.2W 105 KT 120 MPH 36H 23/1800Z 22.6N 105.0W 65 KT 75 MPH...INLAND 48H 24/0600Z 25.7N 102.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 60H 24/1800Z...DISSIPATED $$ Forecaster Berg