Tropical Depression Peter Forecast Discussion Number 15
ActuCyclone
22 septembre 2021
000 WTNT41 KNHC 220840 TCDAT1 Tropical Depression Peter Discussion Number 15 NWS National Hurricane Center Miami FL AL162021 500 AM AST Wed Sep 22 2021 Peter is a disorganized tropical depression. The low-level center is fully exposed and currently located a couple of hundred miles north of Puerto Rico. Most of the associated thunderstorm activity remains displaced well east of the center due to about 30 kt of westerly shear. The initial intensity is held at 30 kt based on a 0206 UTC ASCAT-B pass that showed a swath of 25-30 kt winds about 60 n mi north of the center. The ASCAT data also showed that the circulation has become quite elongated. Since the hostile conditions of strong westerly shear and dry air entrainment are not expected to let up, a continued gradual decay of Peter is forecast. The system is still predicted to become a remnant low in 36 hours and dissipate in a few days, but both of these could occur sooner. The depression is moving northwestward, with the latest initial motion estimated to be 310/10 kt. The cyclone is expected to turn northward by tonight and then northeastward by the end of the week as the system moves in the flow on the east side of a deep-layer trough. The NHC track forecast is a little to the east of the previous one and close to an average of the GFS and ECMWF models. Key Messages: 1. Rainfall around the southern periphery of Peter may lead to areas of urban and small stream flooding through Thursday morning across northern Hispaniola, Puerto Rico, and portions of the Virgin Islands. FORECAST POSITIONS AND MAX WINDS INIT 22/0900Z 21.5N 66.1W 30 KT 35 MPH 12H 22/1800Z 22.2N 66.7W 30 KT 35 MPH 24H 23/0600Z 23.2N 66.9W 25 KT 30 MPH 36H 23/1800Z 24.1N 66.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 24/0600Z 25.1N 65.8W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 24/1800Z 26.5N 64.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 25/0600Z...DISSIPATED $$ Forecaster Cangialosi