Tropical Depression Rose Forecast Discussion Number 16
ActuCyclone
22 septembre 2021
000 WTNT42 KNHC 230238 TCDAT2 Tropical Depression Rose Discussion Number 16 NWS National Hurricane Center Miami FL AL172021 1100 PM AST Wed Sep 22 2021 Rose continues to be devoid of deep convection as shear and dry mid-level air has taken their toll on the system. Although Rose appears to be well on its way to post-tropical cyclone status, it seems prudent to maintain advisories a little longer since the system is over warm waters and some convection could return overnight. If that does not occur, Rose is likely to become a remnant low by tomorrow morning, and that is what is indicated in the official forecast. The remnant low is forecast to continue to gradually spin down over the next day or two. The GFS and ECMWF suggest that some convection could re-develop in the 48-96 h time period when the remnants of Rose interact with an upper-level trough, but the NHC forecast once again does not call for re-generation at that time. In fact, the latest forecast calls for the system to become an open trough by 96 h, which is supported by the GFS. Rose has continued to move west-northwestward or 285/9 kt. The cyclone should turn northwestward very soon as it moves around the western flank of a low- to mid-level ridge. Rose or its remnants should then turn northward, northeastward, and then eventually east-northeastward as a deep-layer trough digs southward over the east-central Atlantic. The latest guidance envelope has again shifted westward in the short term, and the updated NHC track forecast has been adjusted accordingly. After 36 h, the official forecast lies near the previous advisory and is close to the various consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 23/0300Z 24.6N 40.9W 30 KT 35 MPH 12H 23/1200Z 25.7N 41.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 24H 24/0000Z 27.2N 42.4W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 24/1200Z 28.4N 41.4W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 25/0000Z 29.0N 39.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 25/1200Z 29.5N 36.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 26/0000Z 30.2N 33.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 27/0000Z...DISSIPATED $$ Forecaster Brown