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| #1144496 (Received by flhurricane at: 4:50 AM 20.Jul.2023) TCDAT5 Tropical Storm Don Discussion Number 25 NWS National Hurricane Center Miami FL AL052023 900 AM GMT Thu Jul 20 2023 Deep convection associated with Don has become a little better organized since the last advisory, with a curved convective band currently developing near and to the north of the center. However, the various subjective and objective satellite intensity estimates have not changed significantly, and thus the initial intensity remains 45 kt. Conditions appear favorable for some strengthening during the next 18-24 h, and the intensity forecast follows the previous forecast in bringing the winds up to 50 kt during this time. After 24 h, the cyclone will be moving over cooler sea surface temperatures, and after 72 h the cyclone should move north of the Gulf Stream into an area where the water temperatures are below 20C. Based on this and forecast dry air entrainment, the new intensity forecast follows the previous forecast in showing Don starting to weaken around 48 h, then it shows a faster rate of weakening after 72 h. The cyclone is forecast to degenerate to a post-tropical low with no convection by 96 h. The initial motion is now 285/6 kt. A low to mid-level ridge is forecast to build north and east of Don during the next 72 h, which should steer the cyclone west-northwestward, northwestward, and eventually northward during the next 72 h. The guidance has shifted a little more westward after 48 h, and thus the 60 and 72 h forecast are a bit to the west of the previous track, However these points lie to the east of the various consensus models, and some additional adjustments may be needed on subsequent advisories. After 72 h, Don is forecast to recurve northeastward along the southern edge of the mid-latitude westerlies. FORECAST POSITIONS AND MAX WINDS INIT 20/0900Z 34.1N 41.6W 45 KT 50 MPH 12H 20/1800Z 34.4N 42.7W 50 KT 60 MPH 24H 21/0600Z 35.0N 44.4W 50 KT 60 MPH 36H 21/1800Z 36.1N 46.3W 50 KT 60 MPH 48H 22/0600Z 37.7N 48.0W 50 KT 60 MPH 60H 22/1800Z 39.3N 49.2W 45 KT 50 MPH 72H 23/0600Z 41.3N 49.7W 45 KT 50 MPH 96H 24/0600Z 45.0N 47.0W 35 KT 40 MPH...POST-TROPICAL 120H 25/0600Z 47.0N 40.0W 30 KT 35 MPH...POST-TROPICAL $$ Forecaster Beven |
