Issued at 800 PM MST Sat Oct 04 2025
000 WTPZ41 KNHC 050245 TCDEP1 Tropical Storm Priscilla Discussion Number 2 NWS National Hurricane Center Miami FL EP162025 800 PM MST Sat Oct 04 2025 The satellite presentation of Priscilla suggests the storm is contending with some shear this evening. The low-level circulation appears to be partially exposed to the east of the central convection. Large curved bands wrap around the northern and western parts of the circulation. The satellite intensity estimates range from 36-45 kt, and the initial intensity is held at 40 kt based on a blend of these estimates and the earlier scatterometer data. The initial motion estimate is an uncertain 325/3 kt. Priscilla has not moved much since earlier today, and recent satellite images suggest there could be a couple of small vortices rotating around a broader system center. While Priscilla continues to organize and the storm remains in weak steering currents, a slow and erratic northward to northwestward motion is expected during the next day or so. By Monday, a somewhat faster northwestward motion is forecast while Priscilla moves between a strengthening ridge over northern Mexico and an upper-level trough over the western U.S. The cross-track model spread increases greatly at days 3-5. This is likely related to differences in the amplitude of the upper trough off the U.S. West Coast, and the strength and positioning of the ridge over northern Mexico during this period. The 96-120 h NHC track forecast was adjusted a bit slower and farther left, following the latest model trends and remaining between the simple and corrected consensus aids. Despite the storm's large size, most of the intensity guidance favors steady to even significant strengthening over the next few days. Warm sea-surface temperatures and strong upper-level divergence should provide favorable conditions for intensification once Priscilla consolidates an inner core. There are indications that moderate easterly shear will persist into early next week, but the large system should be less susceptible to those negative effects once its structure improves. The NHC forecast shows Priscilla reaching hurricane strength by Monday with some continued strengthening thereafter. A weakening trend is forecast beyond 72 h as Priscilla is expected to encounter cooler waters and a drier, more stable environment while gaining latitude. KEY MESSAGES: 1. Tropical storm conditions are possible along portions of the coast of southwestern Mexico within the watch area Sunday and Monday. Interests in the southern portion of Baja California Sur should monitor the progress of Priscilla. 2. Heavy rainfall associated with Priscilla will impact coastal sections of southwestern Mexico through Monday, 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 Mexico and will reach the coasts of west-central Mexico and the southern Baja California peninsula by Monday. These swells are likely to cause life-threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 05/0300Z 15.6N 106.7W 40 KT 45 MPH 12H 05/1200Z 16.0N 106.8W 50 KT 60 MPH 24H 06/0000Z 16.6N 107.1W 60 KT 70 MPH 36H 06/1200Z 17.4N 107.8W 65 KT 75 MPH 48H 07/0000Z 18.4N 108.8W 75 KT 85 MPH 60H 07/1200Z 19.3N 110.0W 80 KT 90 MPH 72H 08/0000Z 20.2N 111.4W 80 KT 90 MPH 96H 09/0000Z 22.3N 114.1W 70 KT 80 MPH 120H 10/0000Z 24.5N 116.5W 50 KT 60 MPH $$ Forecaster Reinhart
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