598 WTPZ42 KNHC 050238 TCDEP2 Tropical Storm Lorena Discussion Number 13 NWS National Hurricane Center Miami FL EP122025 800 PM PDT Thu Sep 04 2025 Lorena has not produced deep convection near its center since about 8 AM this morning. Waves of heavy showers and thunderstorms continue to stream northeastward across Baja California Sur, Sonora, and northern Sinaloa, but this activity cannot be directly linked to Lorena's circulation. Weakening is assumed to have occurred since the earlier aircraft and ASCAT data, and the intensity is set at 40 kt based on a blend of Dvorak CI numbers and objective numbers (which are between 30 and 45 kt). With Lorena over cool waters and southwesterly shear only expected to increase, deep convection is not forecast to redevelop, and Lorena is likely to become post-tropical Friday morning. Winds will continue to steadily decrease, with the remnant low likely to dissipate by late Sunday. Lorena has been moving west of the dynamical model guidance over the past 6 to 12 hours, and the best-performing track models since this morning have been the simple shallow Trajectory and Beta Advection (TABS) models. Given that the circulation will remain shallow, the new NHC track forecast blends the TABS models with the latest GFS-ECWMF mean and HCCA consensus aid. This puts the new forecast west of the previous prediction by a somewhat noticeable degree, showing more of a slow northwestward motion instead of northward trajectory. Abundant moisture will continue to stream northeastward away from Lorena even though it is weakening. Significant rainfall and flash flooding has already occurred over portions of Baja California Sur, and the risk of life-threatening flash flooding will continue across portions of Baja California Sur and Sonora through Friday, and southern Arizona and New Mexico through Saturday. Key Messages: 1. Heavy rainfall associated with Lorena will continue to impact Baja California Sur and Sonora Mexico through Friday. This will increase the risk of life-threatening flash floods and mudslides across northwest Mexico. 2. Moisture from Lorena will contribute to heavy rainfall concerns across Arizona and New Mexico through Saturday. Isolated to scattered instances of flash flooding are possible across Arizona into Saturday. 3. Life-threatening surf and rip current conditions will affect portions of the western coast of Baja California Sur through Friday. FORECAST POSITIONS AND MAX WINDS INIT 05/0300Z 24.6N 115.1W 40 KT 45 MPH 12H 05/1200Z 25.0N 115.3W 30 KT 35 MPH...POST-TROP/REMNT LOW 24H 06/0000Z 25.3N 115.4W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 06/1200Z 25.7N 115.8W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 07/0000Z 26.1N 116.6W 20 KT 25 MPH...POST-TROP/REMNT LOW 60H 07/1200Z 26.5N 117.6W 15 KT 15 MPH...POST-TROP/REMNT LOW 72H 08/0000Z...DISSIPATED $$ Forecaster Berg
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