ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM Tropical Storm Otis Discussion Number 24 NWS National Hurricane Center Miami FL EP152017 800 AM PDT Sun Sep 17 2017 Otis continues to gradually strengthen. Satellite images show hints of an eye starting to form, and convection just outside the center has been increasing during the past few hours. A blend of the TAFB Dvorak classification and ADT values from CIMSS at the University of Wisconsin supports increasing the winds to 50 kt, though this could be conservative based on the current structure. Otis has a little more time to strengthen since the storm is expected to remain in an environment of low wind shear and over 27 deg C waters. After 24 hours, however, lower SSTs, drier air, and an increase in wind shear should cause weakening. Even though SSTs warm along the expected path by the end of the forecast period, the models continue to show Otis decaying due to unfavorable atmospheric conditions. The cyclone is 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 tropical storm has now turned to the north, as expected, at a very slow forward speed. This slow north to north-northwest motion is expected during the next 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. Only minor changes were made to the previous NHC track forecast, and this one lies close to the various consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 17/1500Z 16.3N 127.3W 50 KT 60 MPH 12H 18/0000Z 17.1N 127.4W 55 KT 65 MPH 24H 18/1200Z 18.0N 127.5W 55 KT 65 MPH 36H 19/0000Z 18.8N 127.7W 50 KT 60 MPH 48H 19/1200Z 18.9N 128.3W 45 KT 50 MPH 72H 20/1200Z 18.1N 130.1W 35 KT 40 MPH 96H 21/1200Z 17.0N 133.1W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 22/1200Z 15.7N 136.6W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Cangialosi NNNN