ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM Tropical Storm Otis Discussion Number 28 NWS National Hurricane Center Miami FL EP152017 800 AM PDT Mon Sep 18 2017 Otis is weakening at a remarkable rate. Only 12 hours ago, the cyclone had an eye, but now most of the deep convection has dissipated entirely. The cloud pattern now only supports an intensity of about 45 kt, but Dvorak intensity estimates are constrained to higher values by the rules of the technique. Given the small size of Otis, it seems possible that this is a rare case where the intensity is dropping faster than the Dvorak technique allows. The initial intensity has been lowered to 60 kt, but it is possible that Otis is even weaker than this. Continued rapid weakening is expected, and most of the dynamical models show Otis becoming a remnant low within about 36 h. The GFS and ECMWF maintain a weak surface low for another couple days after that, but suggest it will dissipate entirely shortly after 96 h. Otis has continued to move northward over the past 6 hours, but it appears to be slowing down. As the circulation becomes shallower over the next 12 to 24 hours, Otis will be increasingly steered by the low-level northeasterly flow associated with a ridge over the central Pacific. This should cause the cyclone to make a sharp turn toward the southwest later today or early tomorrow morning. Little change has been made to the track forecast, which is close to an average of the HCCA and TVCX consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 18/1500Z 19.0N 127.4W 60 KT 70 MPH 12H 19/0000Z 19.4N 127.6W 40 KT 45 MPH 24H 19/1200Z 19.3N 128.1W 30 KT 35 MPH 36H 20/0000Z 18.7N 128.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 20/1200Z 17.8N 130.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 21/1200Z 16.0N 132.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 22/1200Z 14.5N 135.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 23/1200Z...DISSIPATED $$ Forecaster Zelinsky NNNN