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#1150411 (Received by flhurricane at: 4:48 PM 30.Aug.2023) TCDAT3 Hurricane Franklin Discussion Number 41 NWS National Hurricane Center Miami FL AL082023 500 PM AST Wed Aug 30 2023 The cloud pattern of Franklin has become oblong this afternoon, likely due to increasing westerly shear associated with Idalia`s upper-level outflow. A ring of cold infrared cloud tops still surrounds the large eye of the hurricane, which is now somewhat elliptical in shape. The initial intensity is held at 90 kt, which is supported by a T5.0 Dvorak classification from TAFB and UW-CIMSS objective estimates between 85-90 kt. Radar images from Bermuda show an outer rain band is spreading over the island, which will likely result in gusty winds while it passes over the region. Franklin is moving northeastward (55/11 kt) between a deep-layer trough over the northeastern United States and a high pressure ridge over the central Atlantic. The track guidance remains in good agreement on the hurricane moving generally east-northeastward and away from Bermuda during the next couple of days, and little change was necessary to this part of the forecast. There are still along-track differences in the global models regarding Franklin`s track at days 3-5 related to its interaction with the upper trough. But, there is at least general agreement that the cyclone will turn northeastward after it merges with a frontal system over the northern Atlantic. The updated NHC track forecast remains relatively close to the HFIP corrected consensus approach (HCCA) aid during this period. The satellite structure of Franklin is gradually degrading, and the increasing shear that is forecast should keep the hurricane on a weakening trend. The updated intensity forecast is fairly similar to the previous one, with the most notable change being that Franklin is now forecast to become a powerful extratropical cyclone by 72 h. Some of the global guidance suggests this could occur even sooner, so future forecast adjustments may be necessary. Although weakening is forecast, the wind field is likely to grow in size as Franklin moves deeper into the mid-latitudes. KEY MESSAGES: 1. Tropical storm conditions, mainly in gusts, are expected on Bermuda into this evening while Franklin passes north of 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 day or two. FORECAST POSITIONS AND MAX WINDS INIT 30/2100Z 34.2N 65.9W 90 KT 105 MPH 12H 31/0600Z 34.9N 63.9W 85 KT 100 MPH 24H 31/1800Z 35.8N 60.8W 75 KT 85 MPH 36H 01/0600Z 36.9N 57.4W 70 KT 80 MPH 48H 01/1800Z 38.1N 53.9W 65 KT 75 MPH 60H 02/0600Z 39.7N 50.7W 65 KT 75 MPH 72H 02/1800Z 41.6N 47.5W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 03/1800Z 45.0N 42.4W 45 KT 50 MPH...POST-TROP/EXTRATROP 120H 04/1800Z 50.0N 37.5W 40 KT 45 MPH...POST-TROP/EXTRATROP $$ Forecaster Reinhart |