Show Selection: |
#902147 (Received by flhurricane at: 10:59 AM 09.Sep.2017) TCDAT1 Hurricane Irma Discussion Number 42 NWS National Hurricane Center Miami FL AL112017 1100 AM EDT Sat Sep 09 2017 The interaction of Irma`s circulation with Cuba has resulted in some weakening of the hurricane. Data from an Air Force plane indicate that the maximum winds are now 110 kt. However, once the circulation moves away from Cuba, restrengthening is forecast and Irma is expected to remain a very dangerous hurricane for the next 2 days while moving very near the Florida peninsula. The eye has been moving toward the west or 280 degrees at about 8 kt. The hurricane is about the reach the southwestern portion of the subtropical high, and the expected turn to the northwest and north-northwest should begin soon. The track guidance is tightly packed and takes the hurricane over the Florida Keys and near or over the Florida Peninsula. The NHC forecast is in the middle of the guidance envelope and given the good agreement among models, the confidence in the track forecast is high. Irma is now under the scope of Key West radar, so hourly updates will begin at 1600 UTC. KEY MESSAGES: 1. Irma will continue to bring life-threatening wind, storm surge, and rainfall hazards to portions of the Bahamas and the north coast of Cuba, especially over the adjacent Cuban Keys, through tonight. 2. Irma is expected to make landfall in Florida as an extremely dangerous major hurricane, bringing life-threatening wind impacts to much of the state regardless of the exact track of the center. Wind hazards from Irma are also expected to spread northward along the coast of Georgia and South Carolina where a Hurricane Watch has been issued. 3. There is an imminent danger of life-threatening storm surge flooding in portions of central and southern Florida, including the Florida Keys, where a Storm Surge Warning is in effect. The threat of catastrophic storm surge flooding is highest along the southwest coast of Florida, where 10 to 15 feet of inundation above ground level is expected. This is a life-threatening situation and everyone in these areas should immediately follow any evacuation instructions from local officials. 4. Irma is expected to produce very heavy rain and inland flooding. Total rain accumulations of 10 to 20 inches, with isolated amounts of between 20 and 25 inches, are expected over the Florida Keys, the Florida peninsula, and southeast Georgia from Saturday through Monday. Significant river flooding is possible in these areas. Early next week Irma will also bring periods of heavy rain to much of the southeast United States where an average of 2 to 6 inches is forecast, with isolated higher amounts, from North and South Carolina to Tennessee and eastern Alabama. This includes some mountainous areas which are more prone to flash flooding. Residents throughout the southeast states should remain aware of the flood threat and stay tuned to forecasts and warnings. FORECAST POSITIONS AND MAX WINDS INIT 09/1500Z 22.8N 79.8W 110 KT 125 MPH 12H 10/0000Z 23.4N 80.7W 115 KT 130 MPH 24H 10/1200Z 24.5N 81.6W 120 KT 140 MPH 36H 11/0000Z 26.4N 82.1W 120 KT 140 MPH 48H 11/1200Z 29.0N 82.8W 100 KT 115 MPH 72H 12/1200Z 34.5N 86.0W 25 KT 30 MPH...POST-TROP/INLAND 96H 13/1200Z 36.0N 89.0W 25 KT 30 MPH...POST-TROP/INLAND 120H 14/1200Z 37.0N 88.5W 20 KT 25 MPH...POST-TROP/INLAND $$ Forecaster Avila |