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| #1106316 (Received by flhurricane at: 10:41 AM 08.Sep.2022) TCDAT5 Post-Tropical Cyclone Danielle Discussion Number 30 NWS National Hurricane Center Miami FL AL052022 300 PM GMT Thu Sep 08 2022 Satellite imagery this afternoon has shown Danielle develop a clear comma-shaped cloud shield, a hallmark of an extratropical cyclone. In addition, an ASCAT-B pass near 12Z showed a wind shift, indicative of a front, that extended from the center of the cyclone northeastward. Based on these data, Danielle has been classified as post-tropical and this is the last NHC advisory. Peak winds in the ASCAT pass were just above 50 kt, so the intensity of Danielle was lowered slightly to 55 kt. It is worth noting that the peak winds are generally not representative of the impacts associated with extratropical cyclones and gale- to storm-force winds extend well from the center of Danielle. Danielle has begun its long-awaited counterclockwise loop, which should take another 36 to 48 h to complete. After that, the post-tropical cyclone is forecast to move initially southeastward, then eastward as it is caught within the flow of a broader mid-latitude trough moving eastward over the northeastern Atlantic. The track forecast for the post-tropical cyclone is based heavily on the multi-model consensus TVCN. All guidance indicates the cyclone will gradually weaken, both in terms of maximum winds and size through the end of the forecast period. Danielle continues to produce a large area of very rough seas over the central-north Atlantic. More information about the post-tropical cyclone can be found in High Seas Forecasts issued by the UKMET office under WMO header FQNT21 EGRR and on the web at metoffice.gov.uk/weather/specialist-forecasts/coast-and-sea/high- seas-forecast. Information can also be found in Meteo France`s High Seas Forecast at weather.gmdss.org/II.html. FORECAST POSITIONS AND MAX WINDS INIT 08/1500Z 47.9N 31.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 12H 09/0000Z 49.5N 31.2W 55 KT 65 MPH...POST-TROP/EXTRATROP 24H 09/1200Z 49.9N 33.1W 50 KT 60 MPH...POST-TROP/EXTRATROP 36H 10/0000Z 48.3N 33.5W 45 KT 50 MPH...POST-TROP/EXTRATROP 48H 10/1200Z 45.2N 29.1W 40 KT 45 MPH...POST-TROP/EXTRATROP 60H 11/0000Z 43.4N 23.8W 40 KT 45 MPH...POST-TROP/EXTRATROP 72H 11/1200Z 41.5N 19.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 12/1200Z 41.0N 13.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 13/1200Z 43.0N 9.4W 30 KT 35 MPH...POST-TROP/EXTRATROP $$ Forecaster D. Zelinsky |
