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| #1020205 (Received by flhurricane at: 11:00 PM 06.Oct.2020) TCDAT1 Hurricane Delta Discussion Number 10 NWS National Hurricane Center Miami FL AL262020 1000 PM CDT Tue Oct 06 2020 Observations from a NOAA Hurricane Hunter aircraft and conventional and microwave satellite imagery indicate that Delta has not intensified since earlier today. The central pressure has risen somewhat and the current intensity estimate, 115 kt, is probably generous based on flight-level and SFMR-observed surface winds from the NOAA plane. Although the hurricane continues to have very deep convection near and over the center, the cloud pattern lacks well-defined banding features, and an eye is not evident on either geostationary or polar-orbiting satellite images. Surveillance data from the NOAA G-IV aircraft suggest that Delta`s circulation does not extend as markedly into the upper troposphere as one would expect for a major hurricane. Given the current state of the system, not much strengthening seems likely before the center reaches northeastern Yucatan tomorrow morning. Some weakening is likely due to the interaction with land during the next 12-18 hours. Re-intensification over the southern Gulf of Mexico is still expected, but when Delta reaches the northern Gulf, lower oceanic heat content is likely to cause at least slight weakening. The official intensity forecast is somewhat above most of the model guidance, but not much different from the regional hurricane models, HWRF and HMON, over the northern Gulf. Fixes from the aircraft indicate a continued west-northwestward motion at just a slightly slower forward speed, 300/14 kt. The track forecast reasoning is basically unchanged from earlier today. Delta should move along and around the southwestern and western periphery of a mid-tropospheric anticyclone centered just east of Florida for the next couple of days. Around 72 hours, the flow ahead of a shortwave trough over the south-central United States should cause the tropical cyclone to turn north-northeastward and move across the central Gulf coast late Friday or early Saturday. The official track forecast remains close to the dynamical model consensus, TVCA. Key Messages: 1. Life-threatening storm surge and potentially catastrophic wind damage are expected within portions of the northern Yucatan Peninsula of Mexico beginning tonight. All preparations to protect life and property should be rushed to completion. 2. Heavy rainfall will affect portions of the Cayman Islands, western Cuba and the northern Yucatan Peninsula through midweek. This rainfall could lead to significant flash flooding and mudslides. The potential for heavy rain, flash and possible minor river flooding will increase across portions of the central Gulf Coast, Tennessee Valley, and southeastern United States as Delta moves inland later this week. 3. There is an increasing likelihood of life-threatening storm surge and dangerous hurricane-force winds, especially along the coasts of Louisiana and Mississippi, beginning on Friday. Residents in these areas should ensure they have their hurricane plan in place and follow advice given by local officials. Storm surge and hurricane watches will likely be issued for portions of the northern Gulf Coast on Wednesday. FORECAST POSITIONS AND MAX WINDS INIT 07/0300Z 19.5N 85.1W 115 KT 130 MPH 12H 07/1200Z 20.9N 87.1W 115 KT 130 MPH...INLAND 24H 08/0000Z 22.3N 89.8W 105 KT 120 MPH...OVER WATER 36H 08/1200Z 23.6N 91.7W 110 KT 125 MPH 48H 09/0000Z 25.0N 92.7W 115 KT 130 MPH 60H 09/1200Z 26.8N 92.8W 115 KT 130 MPH 72H 10/0000Z 29.0N 92.2W 110 KT 125 MPH 96H 11/0000Z 33.0N 89.8W 50 KT 60 MPH...INLAND 120H 12/0000Z 36.0N 86.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Pasch |