000 WTPZ45 KNHC 090237 TCDEP5 Tropical Storm Olaf Discussion Number 6 NWS National Hurricane Center Miami FL EP152021 900 PM MDT Wed Sep 08 2021 Olaf appears to be gradually strengthening. Deep convection has been increasing over the center, and banding features are becoming a little more pronounced. The latest Dvorak estimates range from 35 to 45 kt. Since the system appears to be better organized from the time of the ASCAT pass earlier today, the initial intensity is nudged up and set near the high end of the estimates at 45 kt. Satellite images and recent microwave data suggest that the center of Olaf is a little to the east of the previous track, and the latest initial motion estimate is 335/6 kt. Olaf is expected to move generally northwestward for another 24 to 36 hours, which should bring the system just off the coast of southern Baja California Sur during that time. There is some spread in the models on how close the storm will get to the coastline, with the GFS to the east of the official forecast and the UKMET and ECMWF to the west and farther offshore. Beyond 36 hours, Olaf is expected to be located to the south of a strong mid-level ridge and that will cause a turn to the west-northwest away from Mexico. The NHC track forecast is adjusted again to the east of the previous one in the short term and then to the south of the previous one at the longer lead times. The new track forecast lies near the middle of the guidance envelope, near the various consensus aids. Olaf is located over warm waters, and embedded in a low wind shear and fairly moist environment. These conditions should allow for additional strengthening during the next day or so. Although not explicitly forecast, Olaf could become a hurricane when it is just off the coast of southern Baja California Sur, and a hurricane watch remains in effect for the possibility of those winds occurring on land. By Friday, a combination of cooler waters and a much drier environment should cause steady weakening, and the system is likely to become a remnant low over the weekend. The NHC intensity forecast lies close to the IVCN and IVDR consensus models. Key Messages: 1. Olaf is forecast to strengthen to near hurricane intensity while it passes offshore of the southern portion of Baja California Sur Thursday and Friday. Tropical storm conditions are expected and hurricane conditions are possible across that area beginning late Thursday. Interests there should continue to monitor the progress of Olaf. 2. Heavy rains associated with Tropical Storm Olaf are possible across portions of far southern Baja California Sur Thursday through Friday. This will pose a threat of flash flooding and mudslides. FORECAST POSITIONS AND MAX WINDS INIT 09/0300Z 20.0N 108.0W 45 KT 50 MPH 12H 09/1200Z 20.8N 108.7W 55 KT 65 MPH 24H 10/0000Z 21.9N 109.9W 60 KT 70 MPH 36H 10/1200Z 22.8N 111.4W 60 KT 70 MPH 48H 11/0000Z 23.4N 113.0W 55 KT 65 MPH 60H 11/1200Z 23.5N 114.4W 45 KT 50 MPH 72H 12/0000Z 23.3N 115.7W 35 KT 40 MPH 96H 13/0000Z 22.6N 118.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 14/0000Z 21.7N 121.3W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Cangialosi