583 WTPZ45 KNHC 012037 TCDEP5 Tropical Storm Rosa Discussion Number 27 NWS National Hurricane Center Miami FL EP202018 200 PM PDT Mon Oct 01 2018 Rosa has no deep convection near its center, but there are plenty of rain-bearing clouds over areas well to the north and northeast of the center, including the northern Baja California peninsula, Sonora, and portions of the southwestern United States. The scatterometer recently missed Rosa, but assuming a steady spin down since the last overpass 12 hours ago, the advisory intensity is set at 35 kt. Continued weakening, due to very strong vertical shear, cool waters, and then interaction with land, should reduce Rosa to a tropical depression very soon. Rosa is likely to degenerate into a remnant low over the southwestern United States tomorrow. The cyclone continues moving north-northeastward, or 030/9 kt. The track forecast philosophy is the same as in the previous advisory package. The flow ahead of a broad mid-level trough should advect Rosa, or its remnant, north-northeastward until dissipation. The official track forecast continues to follow the multi-model consensus closely. 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 01/2100Z 28.1N 116.2W 35 KT 40 MPH 12H 02/0600Z 29.9N 115.2W 30 KT 35 MPH...INLAND 24H 02/1800Z 32.7N 114.0W 25 KT 30 MPH...POST-TROP/INLAND 36H 03/0600Z 35.5N 113.0W 20 KT 25 MPH...POST-TROP/INLAND 48H 03/1800Z...DISSIPATED $$ Forecaster Pasch