Tropical Storm Wanda Forecast Discussion Number 22
ActuCyclone
5 novembre 2021
000 WTNT41 KNHC 050852 TCDAT1 Tropical Storm Wanda Discussion Number 22 NWS National Hurricane Center Miami FL AL212021 900 AM GMT Fri Nov 05 2021 Wanda's cloud pattern remains about the same as it was yesterday evening, with bands of moderately deep convection mainly over the western half of the circulation. Dry and stable air is apparently limiting convection over the eastern semicircle of the cyclone. The current intensity estimate is held at 45 kt for this advisory, which is somewhat higher than Dvorak estimates but in good agreement with earlier scatterometer observations. This seems reasonable given that the cloud pattern has changed little overnight. The latest center fixes indicate that the cyclone is now moving east-southeastward, or 120/5 kt. Wanda is expected to turn southeastward today, and then southward on Saturday as a mid-tropospheric ridge builds to the north and west of the cyclone. After that time, a deep-layer trough is expected to approach Wanda, resulting in a turn to the northeast at an increasing forward speed. The official forecast is similar to the dynamical track model consensus. Since Wanda should move over slightly warmer waters and the shear is not expected to increase during the next couple of days, this should allow the storm to at least maintain its intensity or strengthen a bit. After about 48 hours, vertical shear is predicted to increase significantly. However, baroclinic effects associated with an approaching strong front could offset the weakening process. By 72 hours, the global models indicate that Wanda will become embedded within the frontal zone, and thus have made the transition to an extratropical cyclone. The NHC intensity forecast is close to the latest corrected consensus model guidance. FORECAST POSITIONS AND MAX WINDS INIT 05/0900Z 41.8N 38.0W 45 KT 50 MPH 12H 05/1800Z 40.3N 37.8W 45 KT 50 MPH 24H 06/0600Z 38.2N 37.9W 45 KT 50 MPH 36H 06/1800Z 37.8N 37.6W 45 KT 50 MPH 48H 07/0600Z 39.3N 35.3W 50 KT 60 MPH 60H 07/1800Z 43.0N 31.4W 50 KT 60 MPH 72H 08/0600Z 47.5N 26.5W 50 KT 60 MPH...POST-TROP/EXTRATROP 96H 09/0600Z 53.0N 20.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 120H 10/0600Z...DISSIPATED $$ Forecaster Pasch