000 WTPZ42 KNHC 022059 TCDEP2 Tropical Storm Lorena Discussion Number 4 NWS National Hurricane Center Miami FL EP122025 Issued by the NWS Weather Prediction Center College Park MD 200 PM MST Tue Sep 02 2025 A 1548z METOP-B ASCAT pass provided solid coverage of Lorena's overall wind field with also resulted in a northward adjustment to the initial position. Since the ASCAT pass, GOES-East visible imagery continues to show improving overall organization within an ideal environment for further strengthening. Symmetric banding features support Dvorak DT numbers of 3.0 and 3.5 from TAFB and SAB, respectively. The recent inner core convection bursting with cloud tops below -80C further suggest a strengthening trend, even without recent microwave imagery to analyze its inner core structure. The initial intensity is set at 45 kt, as a blend of the two operational Dvorak estimates, along with other objective intensity estimates. Since the prior advisory, Lorena is moving a bit faster at 13 kt to the northwest as its being steered by the southwestern periphery of the larger scale mid-level ridge. With the small northward readjustment of position, the northwestward track will continue through the next 48 hours, but this brings the center and wind field closer to Baja California compared to the prior track forecast. As such, the overall forecast track is a bit faster and shifted north and east relative to prior forecast, following trends in the latest track guidance. Due to the uncertainty that Tropical Storm force winds may affect areas along the southwestern coasts of Baja California Sur, the Government of Mexico has issued Tropical Storm Watches from Cabo San Lucas northward to Cabo San Lazaro. Any further deviations north and/or eastward may result in further expansion of watches and/or warning conditions over the next 24 to 48 hours. Deep layer vertical shear and overall decaying sea-surface environment will slow the forward speed, with slow recurvature expected after 48 hours west of Baja California Sur. The shear results in an expanding track forecast suite, though will continue to prior trends and overall means recurving the cyclone toward the central Baja California with initial landfall forecast after 72 hours. What remains of the circulation will cross the Peninsula tracking northeast with a second landfall along coastal Sonora towards the end of the forecast period. Lorena is expected to remain fairly small inner core, though with ample moisture and warm sea-surface temperatures for the next 24 to 36 h, forecasts are for steady intensification toward hurricane status by Wednesday. There is some potential that Lorena may rapidly intensify in the short term given its structure and favorable environment. As Lorena crosses the 26 C isotherm in 2-3 days, vertical wind shear will also increase and the overall intensity should start to weaken by late in the week. As the cyclone turns northeastward, slow weakening is expected with eventual dissipation over Sonora by Saturday. The intensity forecast is on the higher end of the guidance envelope. 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. Due to the uncertainty that Tropical Storm force winds may affect areas along the southwestern coasts of Baja California Sur, the Government of Mexico has issued Tropical Storm Watches from Cabo San Lucas northward to Cabo San Lazaro. Residents should closely monitor the latest forecast updates and ensure that they have their preparedness plan in place. FORECAST POSITIONS AND MAX WINDS INIT 02/2100Z 19.4N 109.0W 45 KT 50 MPH 12H 03/0600Z 20.6N 110.4W 55 KT 65 MPH 24H 03/1800Z 21.8N 112.0W 65 KT 75 MPH 36H 04/0600Z 22.9N 113.1W 75 KT 85 MPH 48H 04/1800Z 24.1N 113.8W 70 KT 80 MPH 60H 05/0600Z 25.1N 113.8W 55 KT 65 MPH 72H 05/1800Z 26.2N 113.3W 45 KT 50 MPH 96H 06/1800Z 28.4N 111.8W 35 KT 40 MPH 120H 07/1800Z 29.9N 110.3W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Gallina/Papin
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