ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM Hurricane Otis Discussion Number 25 NWS National Hurricane Center Miami FL EP152017 200 PM PDT Sun Sep 17 2017 Otis continues to surprise us. Satellite images indicate that the eye has become more distinct during the past few hours, and the deep convection is wrapping around that center. The cyclone is currently undergoing rapid intensification, and the initial intensity is increased significantly to 90 kt based on a blend of the latest satellite estimates. This makes Otis a category 2 hurricane on the Saffir-Simpson Hurricane Wind Scale. Even though Otis is a powerful cyclone, recent ASCAT data confirms that the wind field of the system is extremely compact. Some additional strengthening is likely during the next 12 hours or so while the hurricane remains in an environment of low wind shear and over 27 deg C waters. After that time, however, lower SSTs, drier air, and an increase in wind shear should cause rapid weakening. Even though Otis will be moving over warmer waters by the end of the forecast period, the models continue to show Otis decaying due to unfavorable atmospheric conditions. The cyclone is still forecast to become a remnant low by day 4 based on the global models, but this is a low confidence prediction at this time. The hurricane continues to move slowly northward at 4 kt. A slow north to north-northwest motion is expected during the next 24 to 36 hours while Otis moves on the west side of a weak mid-level ridge. Thereafter, a faster west and west-southwest motion is expected when the weakening cyclone becomes more influenced by the low-level tradewind flow. This track forecast is not too different from the previous one, and it lies close to the various consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 17/2100Z 17.0N 127.3W 90 KT 105 MPH 12H 18/0600Z 17.7N 127.4W 110 KT 125 MPH 24H 18/1800Z 18.6N 127.6W 90 KT 105 MPH 36H 19/0600Z 19.0N 128.0W 70 KT 80 MPH 48H 19/1800Z 18.8N 128.6W 50 KT 60 MPH 72H 20/1800Z 17.7N 130.7W 35 KT 40 MPH 96H 21/1800Z 16.4N 133.7W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 22/1800Z 15.0N 136.5W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Cangialosi NNNN