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#1022903 (Received by flhurricane at: 10:57 PM 27.Oct.2020) TCDAT3 Tropical Storm Zeta Discussion Number 14 NWS National Hurricane Center Miami FL AL282020 1000 PM CDT Tue Oct 27 2020 Satellite images show that Zeta is becoming better organized tonight with a ragged eye feature now present, plenty of deep convection and a more symmetric appearance. The Air Force Reserve Hurricane Hunter aircraft has found increasing winds on this flight, recently recording peak flight-level winds of 65 kt and a minimum pressure of around 990 mb. The initial wind speed is raised to 60 kt on the basis of the wind data. The improving cloud pattern of Zeta is usually one that favors intensification in the short term. In addition, microwave data from a couple hours ago indicated that a 37 GHz low-level ring was present, which also can be a harbinger of strengthening, and sometimes that strengthening is on the rapid side. Since the storm remains over warm water with fairly light shear, the NHC forecast still anticipates Zeta regaining hurricane intensity within the next 6 hours and making a second landfall as a hurricane. The new NHC forecast is a little higher than the previous one, remaining on the high side of the guidance. After landfall, Zeta is likely to become an extratropical cyclone while it approaches the eastern United States in a couple of days, and become absorbed by the same frontal system. Zeta is moving northwestward a little faster tonight (325/13 kt). The storm is expected to turn northward and move along the western side of a mid-level anticyclone centered east of Florida through Wednesday morning. A deep cold low (responsible for the southern Plains ice storm) approaching from the west will cause Zeta to sharply accelerate north-northeastward and move inland along the southeastern Louisiana coast Wednesday afternoon. The cyclone should continue to accelerate ahead of the trough and move over the southeastern and eastern U.S. through Thursday. Similar to the last forecast, the official track forecast was moved slightly westward during the first 24 hours, not too dissimilar from a consensus of the latest GFS, UKMET and ECMWF forecasts. Given Zeta`s acceleration near landfall, strong winds are likely to spread well inland along the northern Gulf coast Wednesday night. KEY MESSAGES: 1. A life-threatening storm surge is expected along portions of the northern Gulf Coast by late Wednesday, with the highest inundation occurring somewhere between the Mouth of the Pearl River and Dauphin Island, Alabama. Residents in the Storm Surge Warning area should follow any advice given by local officials. 2. Hurricane conditions are expected Wednesday afternoon within portions of the Hurricane Warning area between Morgan City, Louisiana, and the Mississippi/Alabama border. Damaging winds, especially in gusts, will spread well inland across portions of southeast Mississippi and southern Alabama Wednesday night due to Zeta`s fast forward speed. 3. Localized heavy rainfall from Zeta will continue tonight in portions of the Yucatan Peninsula of Mexico and western Cuba where additional flash flooding is possible in urban areas. Between tonight and Thursday, heavy rainfall is expected from portions of the central U.S. Gulf Coast into the Ohio Valley 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 28/0300Z 23.8N 91.2W 60 KT 70 MPH 12H 28/1200Z 26.0N 91.7W 75 KT 85 MPH 24H 29/0000Z 30.2N 89.7W 65 KT 75 MPH...INLAND 36H 29/1200Z 35.0N 84.5W 30 KT 35 MPH...INLAND 48H 30/0000Z 39.5N 74.5W 40 KT 45 MPH...POST-TROP/EXTRATROP 60H 30/1200Z...DISSIPATED $$ Forecaster Blake |