404 WTNT45 KNHC 050841 TCDAT5 Hurricane Danielle Discussion Number 17 NWS National Hurricane Center Miami FL AL052022 900 AM GMT Mon Sep 05 2022 There's been little change in Danielle's cloud pattern during the past 6 hours, and a clear symmetric warm 13C banding eye feature has persisted and has intermittently been closing off. The satellite intensity estimates haven't changed, and the initial intensity is held at 80 kt for this advisory. Little change in strength is forecast through today. Afterward, the cyclone should slowly weaken through the entire period as it moves over cooler water while increasing southwesterly shear disrupts the upper outflow pattern. The CMC, UKMET, and the GFS agree with Danielle to begin an extratropical transition around 36 hours and complete its change by 72 hours (Thursday). This cyclone transformation timeline is reflected in the NHC forecast, and the predicted 5-day intensity closely follows the IVCN and HCCA aids. The hurricane's initial motion is estimated to be 030 at 7 kt, a little faster than previously noted. Danielle should continue to accelerate and move north-northeastward to northeastward through early Tuesday in response to a mid-latitude baroclinic system approaching from the northwest, out of the Canadian Maritimes. By Tuesday night, the cyclone should turn toward the east-northeast within the mid-latitude westerly steering flow and continue in this general motion for 60 hours. A turn back toward the northeast is forecast as an extratropical cyclone on Thursday. It's worth mentioning that earlier today, there was quite a bit of uncertainty (global model cross-track spread) about Danielle's trajectory beyond the mid-period. The GFS and the UKMET predict Danielle will turn back toward the northeast Wednesday in the southwesterly peripheral flow of a larger baroclinic low approaching the cyclone from the northwest Atlantic. However, the ECMWF 12 and 18z runs showed considerably less baroclinic low influence while continuing toward the east-northeast, southwest of the British Isles. The latest 00z run, subsequently, has trended more toward the GFS/UKMET solution, which has resulted in some increase in track forecast confidence. Accordingly, the NHC forecast is again adjusted slightly north of the previous one to align more with a consensus (TVCA) of the models mentioned above. FORECAST POSITIONS AND MAX WINDS INIT 05/0900Z 39.6N 44.4W 80 KT 90 MPH 12H 05/1800Z 40.5N 43.6W 80 KT 90 MPH 24H 06/0600Z 41.4N 42.4W 75 KT 85 MPH 36H 06/1800Z 42.1N 40.6W 75 KT 85 MPH 48H 07/0600Z 42.8N 38.3W 70 KT 80 MPH 60H 07/1800Z 43.8N 35.6W 65 KT 75 MPH 72H 08/0600Z 45.3N 32.5W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 09/0600Z 48.2N 26.1W 55 KT 65 MPH...POST-TROP/EXTRATROP 120H 10/0600Z 50.8N 20.6W 50 KT 60 MPH...POST-TROP/EXTRATROP $$ Forecaster Roberts