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| #1149846 (Received by flhurricane at: 11:06 AM 28.Aug.2023) TCDAT5 Tropical Storm Idalia Discussion Number 8 NWS National Hurricane Center Miami FL AL102023 1000 AM CDT Mon Aug 28 2023 The satellite presentation of the storm has improved this morning with the center more deeply embedded within the deep convection and colder cloud tops. However, recent reconnaissance aircraft data from both the U.S. Air Force Reserve and NOAA indicate that the improved satellite presentation has not yet resulted in an increase in wind speed. The Air Force Hurricane Hunter aircraft has measured peak 850-mb flight-level winds of 68 kt, and a minimum pressure around 990 mb. Based on these data, the initial intensity remains 55 kt this advisory. The Air Force aircraft will be in the storm environment through early afternoon and that data should continue to provide information Idalia`s structure and intensity. Recent satellite and aircraft fixes show that Idalia is moving northward or 360/8 kt. A mid-level trough over the central Gulf of Mexico and a ridge near the Greater Antilles should cause Idalia to move northward at a faster forward speed during the next 12-24 hours. After that time, an even faster north-northeast motion is expected an another mid-level trough moves across the central and eastern portions of the United States. The latest NHC track forecast is again quite similar to the previous forecast. Although the track forecast has been quite consistent, there is still some spread in the guidance by 48 hours, and it cannot be emphasized enough that only a small deviation in the track could cause a significant change in Idalia`s landfall location in Florida due to the paralleling track to the west coast of the state. Although there is still some moderate northwesterly over the storm, intensification seems likely during the next 12-18 hours, and Idalia is forecast to become a hurricane during that time. By Tuesday, the environment over the eastern Gulf of Mexico is expected to become more conducive for strengthening. Steady to rapid intensification is predicted beginning Tuesday while Idalia traverses the warm waters of the eastern Gulf and the upper-level environment becomes more favorable. The NHC intensity forecast again calls for Idalia to reach major hurricane strength before landfall along the Gulf coast of Florida. This forecast has necessitated the issuance of Storm Surge and Hurricane Warnings for portions of the west coast of Florida and Storm Surge and Tropical Storm Watches for portions of the Atlantic coasts of Florida and Georgia. KEY MESSAGES: 1. There is a danger of life-threatening storm surge inundation along portions of the Florida Gulf Coast where a Storm Surge Warning is in effect, including Tampa Bay and the Big Bend region of Florida. Inundation of 7 to 11 feet above ground level is expected somewhere between Chassahowitzka and Aucilla River. Residents in these areas should follow any advice given by local officials. 2. Hurricane conditions are expected within portions of the Hurricane Warning area along the Florida Gulf Coast, with the potential for destructive winds where the core of Idalia moves onshore. Strong winds will also spread inland across portions of northern Florida near the track of the center of Idalia. 3. Areas of flash and urban flooding, some of which may be locally significant, are expected across portions of the west coast of Florida, the Florida Panhandle, and southern Georgia Tuesday into Wednesday, spreading into portions of the eastern Carolinas Wednesday into Thursday. 4. Hurricane-force winds are expected across portions of far western Cuba later today. Heavy rainfall is also expected across portions of western Cuba and may produce areas of flash and urban flooding as well as landslides across western Cuba. FORECAST POSITIONS AND MAX WINDS INIT 28/1500Z 20.8N 85.2W 55 KT 65 MPH 12H 29/0000Z 22.0N 85.2W 65 KT 75 MPH 24H 29/1200Z 23.9N 85.1W 75 KT 85 MPH 36H 30/0000Z 26.4N 84.6W 90 KT 105 MPH 48H 30/1200Z 29.2N 83.5W 100 KT 115 MPH 60H 31/0000Z 31.9N 81.2W 55 KT 65 MPH...INLAND 72H 31/1200Z 33.6N 78.0W 50 KT 60 MPH...OVER WATER 96H 01/1200Z 34.6N 71.2W 50 KT 60 MPH 120H 02/1200Z 34.5N 67.0W 50 KT 60 MPH $$ Forecaster Brown |
