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#1022790 (Received by flhurricane at: 5:05 AM 27.Oct.2020) TCDAT3 Tropical Storm Zeta Discussion Number 11 NWS National Hurricane Center Miami FL AL282020 400 AM CDT Tue Oct 27 2020 Satellite imagery and surface data from Mexico indicated that Zeta made landfall along the coast of the Yucatan Peninsula just north of Tulum near Ciudad Chemuyil just before 0400 UTC. A WeatherFlow observing site just south of Ciudad Chemuyil reported light winds and a minimum pressure of 978 mb. Another WeatherFlow site near Playa del Carmen reported a one-minute sustained wind of 64 kt with a gust to 76 kt. Hurricane-force winds gusts were also reported on Cozumel. Since the time of landfall, the center of Zeta has moved inland over the northern portions of the Yucatan peninsula. Some weakening has likely occurred, so the initial intensity has been reduced to 60 kt. Zeta is forecast to emerge off the northern coast of the Yucatan peninsula over the southern Gulf of Mexico shortly after 1200 UTC today. Although some slight additional weakening is possible while the center moves overland early this morning, environmental conditions consisting of low vertical wind shear and warm water over the southern Gulf of Mexico should allow for re-strengthening over the next 24 hour or so. By the time Zeta moves over the northern Gulf, cooler waters and increasing shear are likely to cause the hurricane`s intensity to level off or perhaps weaken slightly before landfall. Regardless, Zeta is expected to be at or near hurricane intensity at landfall. Given Zeta`s acceleration before landfall, strong winds are likely to spread well inland along northern Gulf coast Wednesday night. The new NHC intensity forecast is again similar to the previous one, and is little above the model consensus, in best agreement with the HWRF model. Zeta is moving northwestward or 305/12 kt. There has been no change to the track forecast reasoning. The hurricane will move around the southwestern portion of a mid-level ridge center east of Florida. By tonight, a vigorous shortwave trough ejecting out of the southwestern United States will cause Zeta to turn northward, and accelerate northward to north-northeastward on Wednesday and Thursday. This will bring Zeta across the north-central Gulf coast late Wednesday and over the southeastern United States on Thursday. The track guidance remains in good agreement with only some slight timing differences. The updated NHC track forecast is again very similar to the previous advisory and close to the various consensus models. The new track, intensity, and wind radii forecasts necessitate the issuance of Storm Surge, Hurricane, and Tropical Storm Warnings for a portion of the northern Gulf coast. KEY MESSAGES: 1. Tropical storm conditions will continue in portions of the northern Yucatan Peninsula of Mexico through this morning. Heavy rainfall is expected across the Yucatan Peninsula, the Cayman Islands, and western Cuba today, which could lead to flash flooding in urban areas. 2. Hurricane conditions and life-threatening storm surge are expected along portions of the northern Gulf Coast by late Wednesday, and Storm Surge and Hurricane Warnings are in effect. Residents in the watch areas should follow any advice given by local officials. 3. Between tonight and Thursday, heavy rainfall is expected from portions of the central U.S. Gulf Coast into the southern Appalachians, and Mid-Atlantic States near and in advance of Zeta. This rainfall will lead to flash, urban, small stream, and minor river flooding. FORECAST POSITIONS AND MAX WINDS INIT 27/0900Z 21.0N 88.4W 60 KT 70 MPH...INLAND YUCATAN 12H 27/1800Z 22.3N 90.1W 65 KT 75 MPH...OVER WATER 24H 28/0600Z 24.4N 91.5W 75 KT 85 MPH 36H 28/1800Z 27.5N 91.2W 75 KT 85 MPH 48H 29/0600Z 31.7N 88.0W 55 KT 65 MPH...INLAND 60H 29/1800Z 36.5N 81.0W 30 KT 35 MPH...INLAND 72H 30/0600Z 40.3N 70.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 31/0600Z...DISSIPATED $$ Forecaster Brown |