Show Selection: |
#901968 (Received by flhurricane at: 10:53 AM 08.Sep.2017) TCDAT1 Hurricane Irma Discussion Number 38 NWS National Hurricane Center Miami FL AL112017 1100 AM EDT Fri Sep 08 2017 Recent data from both NOAA and Air Force reconnaissance planes indicate that Irma`s intensity remains at 130 kt, although this value could be 5 kt higher or lower. The central pressure has been oscillating around 927 mb. The environment continues to be favorable for Irma to maintain its category 4 status, and only unpredictable eyewall replacement cycles could result in intensity fluctuations during the next 48 hours. Nevertheless, the NHC forecast brings Irma near south Florida as a category 4 hurricane. Thereafter, interaction with land and an increase in shear should induce gradual weakening. Plane, satellite and radar fixes from Cuba indicate that the eye of Irma is moving toward the west-northwest or 285 degrees at about 12 kt. The hurricane should continue on this track for the next 24 hours. After that time, Irma will reach the southwestern edge of the subtropical high and begin to turn north-northwestward and northward. This turn will occur, but the precise moment is still uncertain, and that is why NHC emphasizes that nobody should focus on the exact track of the center. The new NHC forecast was adjusted just a little bit westward and is on top the latest ECMWF model and the HFIP corrected consensus. In fact, these two aids are also very close to each other. KEY MESSAGES: 1. Irma is an extremely dangerous Category 4 hurricane and will continue to bring life-threatening wind, storm surge, and rainfall hazards to the Bahamas through Saturday. Hurricane conditions will spread over portions of the north coast of Cuba, especially over the adjacent Cuban Keys, through Saturday. 2. Irma is likely to make landfall in Florida as a dangerous major hurricane, and will bring life-threatening wind impacts to much of the state regardless of the exact track of the center. 3. There is the danger of life-threatening storm surge inundation in southern Florida and the Florida Keys during the next 36 hours, where a Storm Surge Warning is in effect. In particular, the threat of significant storm surge flooding along the southwest coast of Florida has increased, and 6 to 12 feet of inundation above ground level is possible in this area. This is a life-threatening situation. Everyone in these areas should take all actions to protect life and property from rising water and follow evacuation instructions from local officials. 4. Irma is expected to produce very heavy rain and inland flooding. Total rain accumulations of 4 to 12 inches, with isolated amounts of 20 inches are expected over the Florida peninsula Saturday through Monday. The highest amounts are expected over the eastern Florida peninsula and upper Florida Keys. Irma will likely bring periods of heavy rain to much of Georgia, South Carolina, and western North Carolina early next week, including some mountainous areas which are more prone to flash flooding. All areas seeing heavy rainfall from Irma will experience a risk of flooding and flash flooding. FORECAST POSITIONS AND MAX WINDS INIT 08/1500Z 22.0N 75.3W 130 KT 150 MPH 12H 09/0000Z 22.4N 77.1W 130 KT 150 MPH 24H 09/1200Z 22.8N 79.0W 130 KT 150 MPH 36H 10/0000Z 23.7N 80.3W 130 KT 150 MPH 48H 10/1200Z 25.0N 81.0W 125 KT 145 MPH...NEAR THE COAST 72H 11/1200Z 29.3N 82.3W 65 KT 75 MPH...INLAND 96H 12/1200Z 34.0N 85.0W 30 KT 35 MPH...INLAND 120H 13/1200Z 36.0N 87.0W 25 KT 30 MPH...INLAND $$ Forecaster Avila |