Issued at 800 AM MST Tue Sep 02 2025
000 WTPZ42 KNHC 021500 TCDEP2 Tropical Storm Lorena Discussion Number 3 NWS National Hurricane Center Miami FL EP122025 Issued by the NWS Weather Prediction Center College Park MD 800 AM MST Tue Sep 02 2025 GOES-East imagery depicts a steadily improving convective structure, where earlier the presentation was more elongated, but more recently is taking on a banded structure with bursting overshooting tops near the center, suggesting better overall organization of the small core. Recent Dvorak satellite estimates from TAFB/SAB are at 2.5 and 3.5, respectively, indicative of the intensification. As such, initial intensity is set at 40 kt, slightly favoring the TAFB estimate though satellite trends continue to improve. Thus, Tropical Depression Twelve-E has been upgraded to Tropical Storm Lorena. The cyclone is now moving northwestward at 12 kt along the southwestern periphery of a mid-level ridge. The ridge should steer the storm generally northwestward for the next couple of days. However, the strength and therefore, depth of the cyclone will have a sizable impact on its expected track and potential recurvature towards Baja California. Model solutions that are stronger bring the cyclone northward and eastward relative to the overall guidance suite closer to Baja California earlier. Thus interests along Baja California Sur should monitor updates to the track closely. Given overall trends, a slightly faster, northward adjustment to the track was made. The latest track forecast shows landfall in central Baja at 96 hours, but there remains significant spread in the track guidance, with the latest GFS forecast faster and to the east, while the most recent ECMWF forecast is a significant leftward outlier, not ever reaching the Mexican coastline. Given the spread, stay tuned to updates in subsequent forecast packages. Very warm waters and ample deep layer moisture will allow for a steady intensification over the next few days, with increasing potential for Lorena to reach hurricane status in the next next 24 to 48 hours. Lorena is expected to cross the 26 degree C isotherm in 2-3 days. That factor, in combination with increasing southwesterly vertical shear should result in weakening after that time until landfall across the Baja California Peninsula. The latest NHC intensity forecast is higher than the previous cycle, but remains a little under the HCCA consensus aid. Interests in southwestern Mexico and Baja California Sur should monitor the progress of this system. A Tropical Storm Watch could be required for portions of Baja California later today or Wednesday. Key Messages: 1. Heavy rainfall associated with Tropical Storm Lorena will begin to affect Baja California Sur on Wednesday, and southwestern Sonora by Thursday. This will increase the risk of life-threatening flash floods and mudslides, especially in areas of higher terrain. 2. Lorena is forecast to approach the Baja California peninsula later this week. Although it is too soon to specify the exact location and magnitude of wind impacts, residents should closely monitor the latest forecast updates and ensure that they have their preparedness plan in place. Watches could be required for a portion of the Baja California peninsula later today or on Wednesday. FORECAST POSITIONS AND MAX WINDS INIT 02/1500Z 18.3N 107.9W 40 KT 45 MPH 12H 03/0000Z 19.4N 109.5W 50 KT 60 MPH 24H 03/1200Z 20.7N 111.3W 60 KT 70 MPH 36H 04/0000Z 21.9N 112.7W 70 KT 80 MPH 48H 04/1200Z 23.0N 113.8W 70 KT 80 MPH 60H 05/0000Z 23.9N 114.2W 55 KT 65 MPH 72H 05/1200Z 24.9N 114.1W 50 KT 60 MPH 96H 06/1200Z 26.8N 113.2W 40 KT 45 MPH...INLAND 120H 07/1200Z 28.9N 111.7W 30 KT 35 MPH...INLAND $$ Forecaster Gallina
