Subtropical Depression Teresa Forecast Discussion Number 4
ActuCyclone
25 septembre 2021
897 WTNT44 KNHC 251445 TCDAT4 Subtropical Depression Teresa Discussion Number 4 NWS National Hurricane Center Miami FL AL192021 1100 AM AST Sat Sep 25 2021 Teresa has been devoid of deep convection for more than 12 hours now. The cloud pattern consists of a swirl of low-level clouds and a band of showers and thunderstorms located about 250 n mi north of the center. This patch of convection is detached from the low-level circulation, and it appears to be more involved with an upper-level trough to the northeast of Teresa. A 1210 UTC ASCAT-A pass shows that the winds within that convection have decreased, with several vectors in the 25 to 30 kt range. Based on that data, the intensity is lowered to 30 kt, making Teresa a subtropical depression. Teresa is unlikely to redevelop any convection near its center as strong west-southwesterly wind shear continues over the cyclone. This will prevent any opportunity for strengthening. Teresa is expected to become a remnant low later today or this evening and dissipate on Sunday. The global models are in good agreement with this scenario. Teresa has moved little during the past 12 hours, so a stationary motion is currently indicated for this advisory. However, a motion toward the northeast should begin within the next few hours and continue through dissipation as the cyclone moves in the flow ahead of a deep-layer trough. The track forecast was adjusted a little to the east of the previous advisory, and is in agreement with the model consensus. FORECAST POSITIONS AND MAX WINDS INIT 25/1500Z 34.3N 65.0W 30 KT 35 MPH 12H 26/0000Z 35.4N 64.4W 30 KT 35 MPH...POST-TROP/REMNT LOW 24H 26/1200Z 37.2N 62.6W 30 KT 35 MPH...POST-TROP/REMNT LOW 36H 27/0000Z...DISSIPATED $$ Forecaster Hagen/Beven