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| #1150552 (Received by flhurricane at: 4:47 AM 31.Aug.2023) TCDAT3 Hurricane Franklin Discussion Number 43 NWS National Hurricane Center Miami FL AL082023 500 AM AST Thu Aug 31 2023 Franklin continues to slowly succumb to the increasingly unfavorable conditions the large hurricane is embedded in. The large eye that had been evident over the last day or so is no longer observed on infrared satellite imagery, likely due to 25-30 kt of northerly shear affecting the convective structure which now favors the southern side of the storm. This observation is also consistent with the radar reflectivity returns from the Bermuda radar. With that said, both the subjective and objective intensity estimates this morning still support an intensity in the 85-90 kt range. Thus Franklin`s intensity will remain 85 kt this advisory, though this may be generous. Franklin continues to move to the east-northeast this morning at an estimated 070/12 kt. As previously discussed, the hurricane is being steered by the flow between a subtropical ridge to its southeast and a trough now ejecting eastward out of the northeastern U.S. After days of large track spread, the guidance this cycle is in better agreement this morning, showing a continued east-northeast or northeastward motion with gradual acceleration. The latest NHC track forecast is not that much changed from the prior one, though with a bit more acceleration towards the end of the forecast period, trending towards the TVCN and HCCA consensus aids. With continued northerly shear expected to persist another 24 hours, Franklin should continue to weaken in the short-term. There may be a brief period between 24-48 h where the shear temporarily decreases as the hurricane becomes positioned in the right entrance region of a jet streak as it interacts with a mid-latitude trough. This is why the intensity forecast shows the weakening trend briefly pausing in 36-48 h. However, this baroclinic forcing will also likely hasten its transition into an extratropical cyclone, with the latest forecast now showing this being completed by 60 h, consistent with simulated-IR imagery from the GFS and ECMWF at that time. Now that Franklin is moving further away from Bermuda, the Meteorological Service of Bermuda has discontinued the Tropical Storm Warning for the island. KEY MESSAGES: 1. Life-threatening surf and rip currents are occurring along the east coast of the United States and Bermuda. These conditions are expected to continue during the next day or two. FORECAST POSITIONS AND MAX WINDS INIT 31/0900Z 34.9N 63.2W 85 KT 100 MPH 12H 31/1800Z 35.8N 60.9W 75 KT 85 MPH 24H 01/0600Z 37.2N 57.6W 70 KT 80 MPH 36H 01/1800Z 38.7N 53.8W 65 KT 75 MPH 48H 02/0600Z 40.8N 49.6W 65 KT 75 MPH 60H 02/1800Z 43.3N 45.2W 60 KT 70 MPH...POST-TROP/EXTRATROP 72H 03/0600Z 45.5N 40.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 04/0600Z 47.5N 34.9W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 05/0600Z 50.1N 30.0W 50 KT 60 MPH...POST-TROP/EXTRATROP $$ Forecaster Papin |
