000 WTPZ41 KNHC 092055 TCDEP1 Tropical Storm Sergio Discussion Number 42 NWS National Hurricane Center Miami FL EP212018 200 PM PDT Tue Oct 09 2018 Days of slow movement and cold water upwelling appear to have finally taken a toll on Sergio. Cloud top temperatures on the west side of the cyclone have warmed considerably since this morning, and microwave imagery indicates that Sergio's eyewall is no longer fully closed. Dvorak-based intensity estimates have decreased accordingly and now support an initial intensity of only 60 kt. A recent partial ASCAT overpass also showed maximum winds of only 50-55 kt in the eastern semicircle of the cyclone, and these data also support making Sergio a tropical storm. The tropical storm is moving east-northeastward, or 060/8 kt. No important changes were made to the track forecast, which is merely an update of the previous advisory. The tropical storm will likely continue to accelerate toward the east-northeast or northeast over the next few days, before approaching the Baja California peninsula on Friday. The NHC forecast remains near the track consensus at all times and confidence in the track forecast is high. Now that Sergio is moving a little faster, it has a chance to move over slightly warmer waters during the next few hours. The intensity guidance is in fairly good agreement that little additional weakening is likely for the next day or so. Beyond 36 h, faster weakening is still possible as the storm reaches much colder waters and the shear over the tropical storm increases. Rapid weakening and dissipation is expected after Sergio makes its final landfall along the coast of mainland Mexico, though a 96 h point remnant low is maintained again in this advisory to represent the inland movement of Sergio. The NHC forecast is essentially an average of the HCCA and IVCN consensus aids at all forecast hours. The biggest hazard associated with Sergio and its remnants will likely be heavy rain that will affect portions of northwestern Mexico and the U.S. Southern Plains through Sunday. For more information about this potential hazard, see products from the Weather Prediction Center and your local weather forecast office. FORECAST POSITIONS AND MAX WINDS INIT 09/2100Z 16.9N 126.5W 60 KT 70 MPH 12H 10/0600Z 17.5N 125.4W 60 KT 70 MPH 24H 10/1800Z 18.7N 123.4W 55 KT 65 MPH 36H 11/0600Z 20.3N 121.0W 55 KT 65 MPH 48H 11/1800Z 22.7N 118.2W 50 KT 60 MPH 72H 12/1800Z 27.3N 112.0W 40 KT 45 MPH 96H 13/1800Z 31.0N 105.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 14/1800Z...DISSIPATED $$ Forecaster Zelinsky