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| #1240453 (Received by flhurricane at: 4:48 PM 05.Aug.2025) TCDAT4 Tropical Storm Dexter Discussion Number 8 NWS National Hurricane Center Miami FL AL042025 500 PM AST Tue Aug 05 2025 This afternoon Dexter continues to exhibit a pulsing convective structure. After briefly becoming exposed earlier today, the low-level circulation has tucked underneath a renewed convective burst on its down-shear side. Despite its ragged appearance, an earlier scatterometer pass indicated that Dexter's circulation had tightened up some with a smaller radius of maximum wind. The peak wind value retrieved was 35 kt, which still supports a current intensity of 35 kt this advisory. This value is higher than the 18 UTC subjective Dvorak intensity estimates, but a bit lower than the some of the objective intensity estimates (DMINT, SATCON). Dexter continues to move off to the northeast, with the latest motion estimated at 055/11 kt. This direction of motion is expected to continue for the next few days with a gentle bend towards the east-northeast, across the North Atlantic. However, the speed of the forward motion continues to be uncertain, with large along-track spread in the guidance. The GFS continues to be on the slow end, while the ECMWF and Google Deep Mind ensemble mean (GDMI) are on the faster end of the guidance suite. The latest NHC track forecast continues to favor the faster track solutions, and is a blend of the prior forecast track, with some of the more reliable consensus aids (HCCA). Vertical wind shear over the system is now above 30 kt out of the west-southwest, and is forecast to increase further over the next 24-48 hours. However, the majority of the intensity guidance indicates Dexter may strengthen due to baroclinic dynamics from a favorable trough interaction. Thus, the NHC intensity forecast shows some strengthening, peaking Dexter as a 50 kt extratropical cyclone in about 48 hours. This forecast is roughly in the middle of the intensity guidance envelope, though notably lower than the latest HAFS-A/B forecasts, which develop a potent sting-jet-like structure as Dexter becomes extratropical. After the extratropical low occludes, it should gradually weaken, eventually opening up into a trough by the end of the forecast period. FORECAST POSITIONS AND MAX WINDS INIT 05/2100Z 38.6N 62.2W 35 KT 40 MPH 12H 06/0600Z 39.2N 60.5W 35 KT 40 MPH 24H 06/1800Z 39.9N 57.6W 40 KT 45 MPH 36H 07/0600Z 40.6N 53.9W 40 KT 45 MPH 48H 07/1800Z 41.9N 49.8W 50 KT 60 MPH...POST-TROP/EXTRATROP 60H 08/0600Z 43.1N 46.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 08/1800Z 44.0N 42.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 09/1800Z 45.3N 33.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 10/1800Z...DISSIPATED $$ Forecaster Papin |
