Issued at 800 PM MST Wed Oct 08 2025
418 WTPZ41 KNHC 090233 TCDEP1 Tropical Storm Priscilla Discussion Number 18 NWS National Hurricane Center Miami FL EP162025 800 PM MST Wed Oct 08 2025 Some convection has re-developed in association with Priscilla, mainly in disorganized bands well removed from the center. This convection is not well-enough organized to keep the satellite intensity estimates from decreasing. Based on these decreases since the previous advisory, the initial intensity is reduced to 50 kt. The initial motion estimate remains northwestward, or 320/8 kt. As mentioned previously, Priscilla is moving along the southwestern side of a mid-level high pressure ridge near the Texas/Mexico border. In 24 h or so, a large mid-latitude trough or cutoff low near the California coast should cause a northward turn. By 48 h, Priscilla will likely have weakened into a shallow cyclone steered by the low-level flow, which is rather weak. The track guidance has not changed significantly since the last advisory, and the new forecast track is very similar to the previous track. The forecast track takes Priscilla over colder sea surface temperatures and into a drier environment, and these factors should cause continued weakening. The latest simulated satellite imagery from the GFS and ECMWF models forecast the cyclone to stop producing convection in about 36 h, and the new intensity forecast calls for the system to decay to a remnant low at that time. The remnant low is still shown as dissipating by 72 h in agreement with the global models. The new intensity forecast is an update of the previous forecast. KEY MESSAGES: 1. Tropical storm conditions are possible along the Baja California Sur Pacific coastline within the Tropical Storm Watch area for the next several hours. 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, southern Utah, through the Four Corners into southwest Colorado and far northwest New Mexico from Thursday into Saturday. 3. Large swells generated by Priscilla are affecting the Pacific coast of Baja California Sur as well as portions of the coast of southwestern and west-central Mexico. 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 09/0300Z 22.6N 113.6W 50 KT 60 MPH 12H 09/1200Z 23.4N 114.4W 45 KT 50 MPH 24H 10/0000Z 24.6N 115.1W 35 KT 40 MPH 36H 10/1200Z 25.7N 115.2W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 11/0000Z 26.5N 115.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 11/1200Z 27.2N 114.8W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 12/0000Z...DISSIPATED $$ Forecaster Beven
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