000 WTNT44 KNHC 040257 TCDAT4 HURRICANE MATTHEW DISCUSSION NUMBER 24 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142016 1100 PM EDT MON OCT 03 2016 An Air Force Reserve Hurricane Hunter aircraft this evening measured two peak SFMR winds of 125 kt in the northeastern eyewall, along with a peak flight-level wind of 129 kt. The lowest pressure measured by a dropsonde has been 934 mb, down 6 mb since the previous flight. Based on these data, the initial intensity has been increased to 125 kt. Matthew continues to move a little east of due north, or 010/07 kt. There is no change to the previous short-term track forecast reasoning. Matthew is expected to move northward around the western periphery of a strong deep-layer ridge for the next 24 hours, followed by a north-northwestward motion at 36 and 48 hours. That portion of the new forecast track is essentially the same as the previous advisory, bringing Matthew over the southwestern peninsula of Haiti tonight and near or over eastern Cuba on Tuesday. Beyond 48 hours, the GFS has again trended westward, and now lies closer to the UKMET model track. This change might be related to the mid-/upper-level trough currently located over the eastern Gulf of Mexico, which is now forecast to split, with the northern portion lifting out to the northeast and dissipating while the southern portion cuts of into a low pressure system that drops southward over the northwestern Caribbean Sea by 36-48 hours. The new track forecast has again been shifted westward closer to Florida, and lies near a blend of the 18Z GFS and 12Z ECMWF model solutions. Only slight weakening is expected during the next couple of days due to Matthew interacting with the land masses of western Haiti and eastern Cuba. After the hurricane emerges over the Atlantic waters between Cuba and the Bahamas, low vertical wind shear and warm SSTs of near 30C should help Matthew to recover some before southwesterly wind shear increases by 96-120 hours and induces a faster rate of weakening. The new NHC intensity forecast is basically identical to the previous advisory, and closely follows the consensus model IVCN. KEY MESSAGES: 1. Matthew is likely to produce devastating impacts from storm surge, extreme winds, heavy rains, flash floods, and/or mudslides in portions of the watch and warning areas in Haiti, Cuba, and the Bahamas. Please consult statements from the meteorological services and other government officials in those countries. 2. Direct hurricane impacts are possible in Florida later this week. Tropical storm and/or hurricane watches are likely tomorrow morning for portions of the Florida peninsula and the Florida Keys. 3. Tropical storm or hurricane conditions could affect portions of Georgia, South Carolina, and North Carolina later this week or this weekend, even if the center of Matthew remains offshore. It is too soon to specify what, if any, direct impacts Matthew might have on the remainder of the U.S. east coast farther north. At a minimum, very dangerous beach and boating conditions are likely along much of the U.S. east coast later this week and weekend. FORECAST POSITIONS AND MAX WINDS INIT 04/0300Z 16.9N 74.6W 125 KT 145 MPH 12H 04/1200Z 18.3N 74.5W 125 KT 145 MPH 24H 05/0000Z 20.0N 74.4W 120 KT 140 MPH 36H 05/1200Z 21.8N 75.2W 115 KT 130 MPH 48H 06/0000Z 23.4N 76.2W 110 KT 125 MPH 72H 07/0000Z 26.6N 78.7W 105 KT 120 MPH 96H 08/0000Z 30.0N 79.6W 100 KT 115 MPH 120H 09/0000Z 33.3N 77.6W 90 KT 105 MPH $$ Forecaster Stewart