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| #1149377 (Received by flhurricane at: 10:56 AM 25.Aug.2023) TCDAT3 Tropical Storm Franklin Discussion Number 20 NWS National Hurricane Center Miami FL AL082023 1100 AM AST Fri Aug 25 2023 Visible satellite imagery this morning shows that Franklin`s low-level center has become completely exposed, with convection on the southeastern side of the system due to strong vertical wind shear. The Air Force Hurricane Hunters have been in the system this morning and found that the pressure has increased to 1003 mb and the flight-level winds have decreased, though strong convection prevented a full sample of the storm. A blend of subjective and objective satellite estimates are in general agreement with data from the Air Force reconnaissance that show the winds slightly lower than the previous advisory. Therefore, the initial intensity is set to 45 kt. The storm is moving slowly to the east-southeast at about 4 kt, around the base of a broad mid- to upper-level trough. A turn to the east then a northeast motion is expected later today and tonight as ridging builds to the east of Franklin over the central Atlantic and the trough drops southwestward. This system will then turn more northward late this weekend into early next week, with the core of the system probably moving to the west of Bermuda on Monday and Tuesday. By the middle of next week, Franklin is forecast to turn to the northeast and increase in forward motion due to faster flow between the ridge and a mid-latitude trough over eastern Canada and the northeast U.S. The NHC track forecast has shifted southeastward in the short term given the recent motion. At long range, there was once again another shift to the west in the guidance envelope and the official track forecast follows the trend. Strong westerly vertical wind shear should remain over the system for the next 24 hours or so, which will probably limit much strengthening. In a day or two, more significant strengthening is forecast as the wind shear decreases and Franklin remains over very warm sea surface temperatures. Franklin is expected to become a hurricane over the weekend and should reach a peak intensity near major hurricane strength early next week. The cyclone should level off in intensity by day 4, followed by a weakening trend thereafter due to Franklin moving over cooler waters and into a stronger vertical wind shear environment. The intensity forecast is fairly similar to the previous, with the only change being a slightly weaker system in the near term, which lies near the corrected consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 25/1500Z 21.8N 67.8W 45 KT 50 MPH 12H 26/0000Z 22.1N 67.1W 45 KT 50 MPH 24H 26/1200Z 22.8N 66.9W 50 KT 60 MPH 36H 27/0000Z 23.7N 67.5W 55 KT 65 MPH 48H 27/1200Z 25.2N 68.3W 65 KT 75 MPH 60H 28/0000Z 26.8N 69.1W 80 KT 90 MPH 72H 28/1200Z 28.7N 69.4W 95 KT 110 MPH 96H 29/1200Z 33.1N 68.4W 95 KT 110 MPH 120H 30/1200Z 39.0N 63.6W 80 KT 90 MPH $$ Forecaster Kelly/Blake |
