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Tropical Storm Eta Forecast Discussion Number 47
2020-11-12 03:46:12| National Hurricane Center (Atlantic)
Issued at 1000 PM EST Wed Nov 11 2020 000 WTNT44 KNHC 120246 TCDAT4 Tropical Storm Eta Discussion Number 47 NWS National Hurricane Center Miami FL AL292020 1000 PM EST Wed Nov 11 2020 Deep convection intensified over the northern portion of the circulation of Eta over the past few hours, however the overall cloud pattern has not become better organized this evening. Adjusted flight-level and SFMR-observed surface winds from an Air Force Reserve Hurricane Hunter aircraft indicate that the maximum winds are near 55 kt, with the central pressure holding about steady for now. Since the storm will be moving over progressively cooler waters, with strong west-southwesterly shear and some incursions of drier air, gradual weakening is likely up to landfall tomorrow morning. A more rapid weakening is likely after the center crosses the coast tomorrow. The dynamical guidance does not indicate significant restrengthening after Eta emerges into the Atlantic within 24 hours, although some baroclinic forcing could allow the system to maintain its intensity for awhile. The cyclone is likely to be absorbed by a frontal zone in 60-72 hours if not sooner. Center fixes indicate that the motion continues to be just a little to the east of due north, or 010/10 kt. A slight turn toward the right is expected soon, and over the next couple of days Eta should move north-northeastward to northeastward, ahead of a broad mid-level trough, until dissipation. The official track forecast follows the general trajectory of the simple and corrected dynamical model consensus, but is somewhat slower than the consensus guidance in deference to the latest GFS prediction. Key Messages: 1. There is a danger of life-threatening storm surge along portions of the Florida Gulf Coast from Bonita Beach to the Suwannee River, including Tampa Bay and Charlotte Harbor. Residents in this area should follow any advice given by local officials. 2. Tropical-storm-force winds are expected tonight and early Thursday along portions of the Florida Gulf Coast from Bonita Beach to the Suwanee River, and are possible tonight on Thursday from the Suwannee River to the Aucilla River. Interests elsewhere along the Florida Gulf Coast should monitor the progress of Eta. 3. Heavy rainfall from Eta will continue to spread northward across West and Central Florida through Thursday. Additional flash and urban flooding will be possible in South Florida through Thursday, especially across previously inundated areas. Flash, urban, and isolated minor river flooding is expected across portions of West and North Florida through Thursday. FORECAST POSITIONS AND MAX WINDS INIT 12/0300Z 28.3N 83.4W 55 KT 65 MPH 12H 12/1200Z 29.7N 82.4W 40 KT 45 MPH...INLAND 24H 13/0000Z 31.8N 79.8W 35 KT 40 MPH...OVER WATER 36H 13/1200Z 33.7N 76.3W 30 KT 35 MPH 48H 14/0000Z 35.5N 72.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 14/1200Z 37.0N 68.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 15/0000Z...DISSIPATED $$ Forecaster Pasch
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