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| #1150140 (Received by flhurricane at: 5:02 PM 29.Aug.2023) TCDAT3 Hurricane Franklin Discussion Number 37 NWS National Hurricane Center Miami FL AL082023 500 PM AST Tue Aug 29 2023 Franklin has completed an eyewall replacement cycle this afternoon. This was confirmed by an AMSR microwave pass at 1748Z, showing that the outer eyewall has now become the dominant feature and the inner eyewall has completely collapsed. In the last few hours, infrared imagery has depicted cold cloud tops in the deep convection within the new eyewall. The subjective and objective satellite estimates have decreased slightly throughout the day, but still remain around a T5.5 from TAFB and CIMSS ADT. Given these satellite estimates and the structure depicted from microwave imagery, the initial intensity for this advisory will remain 110 kt. Franklin is moving northeastward at around 10 kt. This northeastward motion is expected to continue for the next few days with an increase in forward speed as Franklin rounds the edge of the subtropical ridge and gets caught in the southwesterly flow ahead of a mid-latitude trough moving off the northeast U.S. coast and Atlantic Canada. There still remains a good amount of spread in the track guidance with both along- and cross-track differences beyond 48 h. The NHC track is near the previous advisory and lies in the middle of the guidance envelope, close to the consensus aids. Even though the center of Franklin is forecast to pass to the northwest of Bermuda on Wednesday, tropical-storm-force winds associated with the hurricane are expected to extend well to the southeast of the center. Franklin could fluctuate in intensity now that it has completed the eyewall replacement cycle. But, it should gradually weaken in the near term, as it begins to move northward over cooler waters, with some increase in northwesterly wind shear. Vertical wind shear is forecast to increase further in about 36 h, with further weakening anticipated. The guidance this cycle has come into better agreement with the timing of extratropical transition in about 72 h, and this is now reflected in the latest NHC forecast. KEY MESSAGES: 1. Tropical storm conditions are expected on Bermuda beginning Wednesday morning, when Franklin is forecast to make its closest approach to the island. 2. Life-threatening surf and rip currents are occurring along the east coast of the United States. These conditions are expected to continue during the next several days. FORECAST POSITIONS AND MAX WINDS INIT 29/2100Z 31.4N 69.9W 110 KT 125 MPH 12H 30/0600Z 32.7N 68.7W 105 KT 120 MPH 24H 30/1800Z 34.3N 66.5W 100 KT 115 MPH 36H 31/0600Z 35.4N 63.5W 95 KT 110 MPH 48H 31/1800Z 36.6N 59.8W 85 KT 100 MPH 60H 01/0600Z 37.9N 55.2W 75 KT 85 MPH 72H 01/1800Z 40.6N 50.2W 70 KT 80 MPH...POST-TROP/EXTRATROP 96H 02/1800Z 46.0N 40.2W 65 KT 75 MPH...POST-TROP/EXTRATROP 120H 03/1800Z...DISSIPATED $$ Forecaster Kelly/Reinhart |
