Issued at 800 AM MST Tue Oct 07 2025
000 WTPZ41 KNHC 071449 TCDEP1 Hurricane Priscilla Discussion Number 12 NWS National Hurricane Center Miami FL EP162025 800 AM MST Tue Oct 07 2025 Cloud top temperatures associated with Priscilla's eyewall convection continue to cool, and the structure of the eye has gradually been improving over the past 6 h. Subjective Dvorak classifications from TAFB and SAB range from 90-102 kt, and objective numbers have risen to the 88-102 kt range. The initial intensity has been raised to 95 kt, which is an average of the latest satellite estimates. Intensity guidance is in good agreement that Priscilla should peak in strength in about 12 hours or so while the hurricane remains over warm waters and in a moist, moderate shear environment. Priscilla is now explicitly forecast to become a category 3 hurricane over the next 12 hours. After that, the hurricane is forecast to move over progressively cooler waters, reaching the 26 degree C sea-surface temperature isotherm around hour 36. Priscilla will also be moving into a drier environment as it gains latitude. Therefore, the NHC forecast calls for weakening beginning Wednesday. Southwesterly vertical wind shear is forecast to increase over the cyclone in 3 to 4 days, and simulated satellite images from the GFS and ECMWF models indicates that Priscilla should lose its convection and become a remnant low shortly before the system reaches the Baja California peninsula. Enhanced moisture is likely to be transported northward over portions of the southwestern U.S. late this week, resulting in the potential for heavy rainfall. The hurricane is moving northwestward (305/9 kt) around the southwestern portion of a mid-level ridge over northern Mexico. This motion should continue for the next couple of days while the center of Priscilla moves parallel to, but remains offshore of, the southern Baja California peninsula. By Thursday, an amplifying trough off the U.S. West Coast is forecast to erode the steering ridge to the north of Priscilla. The weakness in the ridge should induce a northward turn later this week and into the weekend. The track models are in fairly good agreement through about 60 h. Thereafter, spread increases, mainly in the along-track direction. The new NHC track forecast is nearly on top of the previous prediction, perhaps a tad faster, and lies in between the faster HFIP Corrected Consensus (HCCA) and the slower Google Deep Mind Ensemble Mean. KEY MESSAGES: 1. Tropical storm conditions are possible along the Baja California Sur Pacific coastline within the Tropical Storm Watch area later today into Wednesday. Interests elsewhere in the Baja California peninsula should monitor the progress of Priscilla. 2. Heavy rainfall associated with Priscilla will impact portions of Baja California Sur today into Wednesday. Its moisture will lead to heavy rainfall across west-central Mexico from today into Thursday morning and across the U.S. Desert Southwest from late this week into this weekend, which could result in flash flooding, particularly in areas of higher terrain. 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. FORECAST POSITIONS AND MAX WINDS INIT 07/1500Z 19.8N 110.1W 95 KT 110 MPH 12H 08/0000Z 20.5N 111.2W 100 KT 115 MPH 24H 08/1200Z 21.5N 112.5W 90 KT 105 MPH 36H 09/0000Z 22.6N 113.8W 75 KT 85 MPH 48H 09/1200Z 23.7N 114.9W 60 KT 70 MPH 60H 10/0000Z 25.1N 115.4W 50 KT 60 MPH 72H 10/1200Z 26.3N 115.5W 40 KT 45 MPH 96H 11/1200Z 28.7N 114.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 12/1200Z 31.5N 113.3W 15 KT 15 MPH...POST-TROP/REMNT LOW $$ Forecaster Hagen
