Issued at 800 AM MST Wed Oct 08 2025
000 WTPZ41 KNHC 081456 TCDEP1 Hurricane Priscilla Discussion Number 16 NWS National Hurricane Center Miami FL EP162025 800 AM MST Wed Oct 08 2025 Priscilla has rapidly weakened over the past 12 hours. Deep convection in the northern semicircle has become almost non-existent, and the convection in the southern semicircle has also decreased in coverage and intensity. Subjective CI numbers were 75 kt at 12Z, but the final-T numbers were 55 kt. Objective intensity estimates from UW-CIMSS have decreased to the 60-70 kt range. Despite the appearance of the deep convection falling apart, a recent 37 GHz GPM pass suggests that Priscilla may still be fairly powerful in the low-levels, below the freezing level, so I have only brought the intensity down to 65 kt, maintaining Priscilla as a hurricane for this advisory. Priscilla is expected to weaken to a tropical storm within the next few hours. The initial motion estimate is slowly northwestward, or 310 degrees at 6 kt. Priscilla is currently moving along the southwestern side of a mid-level high pressure ridge near the Texas/Mexico border. In 36 hours or so, a large trough or cutoff low near the California coast should induce a turn toward the north. By 60 hours, Priscilla will likely have weakened into a shallow cyclone moving in the low-level environmental flow. The official track forecast is very near the previous NHC forecast track through 48 h, but is notably slower and farther south at 60-72 h, and lies close to the HFIP Corrected Consensus (HCCA) approach. Priscilla has weakened faster than anticipated so far, possibly due to enhanced upwelling of cool water due to the cyclone's slow motion. Sea-surface temperatures will continue to rapidly decrease along Priscilla's path, reaching 26 degrees C in about 18 hours. Priscilla is expected to degenerate into a remnant low in about 60 hours, with dissipation just after 72 hours. The official intensity forecast has been lowered from the previous NHC forecast due to the lower initial intensity, and lies near the middle of the model guidance suite. KEY MESSAGES: 1. Tropical storm conditions are possible along the Baja California Sur Pacific coastline within the Tropical Storm Watch area today. Interests elsewhere in the Baja California peninsula should monitor the progress of Priscilla. 2. Moisture associated with Priscilla will lead to heavy rainfall and a flash flood risk across portions of Arizona, Utah, through the Four Corners into southwest Colorado and far northwest New Mexico from Thursday into Saturday morning. 3. Swells generated by Priscilla are affecting portions of the coast of southwestern and west-central Mexico as well as the coast of the southern Baja California peninsula. These swells are likely to cause life-threatening surf and rip current conditions, in addition to some coastal flooding. FORECAST POSITIONS AND MAX WINDS INIT 08/1500Z 21.4N 112.5W 65 KT 75 MPH 12H 09/0000Z 22.2N 113.6W 55 KT 65 MPH 24H 09/1200Z 23.3N 114.7W 50 KT 60 MPH 36H 10/0000Z 24.6N 115.3W 45 KT 50 MPH 48H 10/1200Z 25.9N 115.5W 35 KT 40 MPH 60H 11/0000Z 26.8N 115.4W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 11/1200Z 27.7N 115.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 12/1200Z...DISSIPATED $$ Forecaster Hagen
