219 WTPZ45 KNHC 011432 TCDEP5 Tropical Storm Rosa Discussion Number 26 NWS National Hurricane Center Miami FL EP202018 800 AM PDT Mon Oct 01 2018 Most of Rosa's deep convection has been sheared northeastward over portions of the Baja California peninsula, Sonora, and the southwestern United States. Locally heavy rains are already occurring over those areas. Assuming a gradual weakening of the cyclone since the last scatterometer overpass, and blending Dvorak intensity estimates from TAFB and SAB, gives a current intensity estimate of 40 kt. Since the cyclone will continue to be influenced by strong shear, cooler waters, and then interact with land, continued weakening is likely over the next day or so. Rosa is expected to degenerate into a remnant low by the time it reaches the southwestern United States on Tuesday. The system is moving north-northeastward, or 030/10 kt. Rosa should continue to be steered on that heading, to the east of a broad mid-level trough off the California coast. Some increase in forward speed is expected after Rosa's remnants move into the Desert Southwest. The official track forecast remains very close to the multi-model consensus. Key Messages: 1. The main hazard expected from Rosa or its remnants is very heavy rainfall in Baja California, northwestern Sonora, and the U.S. Desert Southwest. These rains are expected to produce life-threatening flash flooding and debris flows in the deserts, and landslides in mountainous terrain. For more information about potential rainfall in that area, please see products from the Weather Prediction Center and your local NWS forecast office. 2. Tropical storm conditions are affecting portions of the central and northern Baja California peninsula, especially over higher elevations. These conditions could spread into the northern Gulf of California later tonight. Interests in those locations should monitor the progress of Rosa. FORECAST POSITIONS AND MAX WINDS INIT 01/1500Z 27.5N 116.5W 40 KT 45 MPH 12H 02/0000Z 28.9N 115.6W 35 KT 40 MPH 24H 02/1200Z 31.3N 114.3W 30 KT 35 MPH 36H 03/0000Z 34.3N 112.9W 20 KT 25 MPH...POST-TROP/INLAND 48H 03/1200Z 37.0N 112.0W 15 KT 15 MPH...POST-TROP/INLAND 72H 04/1200Z...DISSIPATED $$ Forecaster Pasch