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| #1020583 (Received by flhurricane at: 11:05 AM 09.Oct.2020) TCDAT1 Hurricane Delta Discussion Number 20 NWS National Hurricane Center Miami FL AL262020 1000 AM CDT Fri Oct 09 2020 Reports from NOAA and Air Force Reserve Hurricane Hunter aircraft indicate that Delta has weakened a little since the last advisory. The central pressure has risen to 962 mb, and the strongest 700-mb flight-level winds reported by the NOAA plane were 107 kt. In addition, SFMR wind estimates have been in the 85-95 kt range. Based on these data, the initial intensity is lowered to 100 kt. Delta is moving northward or 360/11 kt between a deep-layer ridge over the eastern Gulf of Mexico and a mid- to upper-level trough over the U.S. Southern Plains. A turn toward the north-northeast is expected during the next few hours, and the center is forecast to cross the southwestern coast of Louisiana late this afternoon or this evening. After landfall, a continued north-northeastward motion should bring the center across central and northeastern Louisiana by the 24 h point. Thereafter, Delta is expected to move generally northeastward through the lower Mississippi and Tennessee Valleys until it dissipates. The track forecast guidance remains tightly clustered, and the new forecast track is little changed from the previous forecast. Increasing vertical shear and decreasing oceanic heat content along the forecast track should cause Delta to continue to weaken before landfall. However, there will still be significant impacts from winds and storm surge (see Key Messages below). After landfall, rapid weakening is anticipated, with Delta expected to weaken to a tropical storm tonight and to a tropical depression by Saturday afternoon or evening. The cyclone is forecast to dissipate between 60-72 h based on the consensus of the global models. Key Messages: 1. Life-threatening storm surge is expected near and east of where Delta makes landfall this evening, and a Storm Surge Warning is in effect from High Island, Texas, to the Mouth of the Pearl River. The highest inundation of 7 to 11 feet is expected somewhere between Rockefeller Wildlife Refuge and Morgan City, Louisiana. Water levels in this area will rise quickly this afternoon and evening as Delta approaches and efforts to protect life and property should be rushed to completion. 2. Hurricane-force winds are expected this afternoon and evening within portions of the Hurricane Warning area, especially along the coast of southwest Louisiana. Hurricane force winds will also spread inland across portions of southern Louisiana near the path of Deltas center this evening and tonight. 3. Heavy rainfall will lead to significant flash flooding and minor to major river flooding in parts of Louisiana today and Saturday. Additional flooding is expected across portions of the central Gulf Coast into the Lower Mississippi Valley. FORECAST POSITIONS AND MAX WINDS INIT 09/1500Z 28.0N 93.8W 100 KT 115 MPH 12H 10/0000Z 30.0N 93.0W 90 KT 105 MPH...INLAND 24H 10/1200Z 32.2N 91.8W 50 KT 60 MPH...INLAND 36H 11/0000Z 33.7N 90.2W 30 KT 35 MPH...INLAND 48H 11/1200Z 35.0N 88.4W 25 KT 30 MPH...INLAND 60H 12/0000Z 36.7N 86.2W 20 KT 25 MPH...POST-TROP/REMNT LOW 72H 12/1200Z...DISSIPATED $$ Forecaster Beven |