992 WTNT44 KNHC 080834 TCDAT4 Hurricane Milton Discussion Number 13 NWS National Hurricane Center Miami FL AL142024 400 AM CDT Tue Oct 08 2024 The structure of Milton has changed significantly overnight. The pinhole eye seen yesterday has filled and earlier aircraft data showed a double eyewall structure. More recent microwave images show only one larger eyewall, and it is clear that Milton is completing an eyewall replacement cycle. These eyewall replacement cycles are common in strong hurricanes and often cause the peak winds to fluctuate, while the wind field generally expands. Based on the aircraft data from a few hours ago, the initial intensity is set at 135 kt. Both the NOAA and Air Force Hurricane Hunters are scheduled to investigate Milton again later this morning. The major hurricane is beginning to gain latitude, and the latest initial motion estimate is 075/10 kt. A turn to the northeast with a slight increase in forward speed is expected later today and Wednesday as the hurricane moves in the flow between a trough digging into the Gulf of Mexico and a ridge near the Greater Antilles. This motion should take the core of Milton to west-central Florida Wednesday night. After the hurricane passes Florida, a faster east-northeastward motion is expected within a more zonal steering flow. Little change was made to the track forecast through landfall, but this prediction is a little slower while the system enters and moves over the Atlantic. Fluctuations in strength due to continued structural changes are likely during the next day or so while Milton moves across the central and eastern Gulf of Mexico. An increase in vertical wind shear will likely cause some weakening before the hurricane reaches Florida, but there is high confidence that Milton will remain an extremely dangerous hurricane when it reaches the state. After landfall, more notable weakening is forecast and Milton is now expected to become extratropical by day 3 when it is over the Atlantic. The NHC intensity forecast lies at the high end of the model guidance in best agreement with the hurricane regional models. Milton is still a relatively compact hurricane, but the wind field is expected to continue to grow in size as it approaches Florida. In fact, the official forecast shows the hurricane and tropical-storm-force winds roughly doubling in size by the time it makes landfall. Therefore, damaging winds, life-threatening storm surge, and heavy rainfall will extend well outside the forecast cone. It is worth emphasizing that this is a very serious situation and residents in Florida should closely follow orders from their local emergency management officials. Milton has the potential to be one of the most destructive hurricanes on record for west-central Florida. Key Messages: 1. Damaging hurricane-force winds and a life-threatening storm surge with destructive waves are expected across portions of the northern coast of the Yucatan Peninsula today. 2. Milton is expected to grow in size and remain an extremely dangerous hurricane when it approaches the west coast of Florida on Wednesday. A large area of destructive storm surge will occur along parts of the west coast of Florida. This is an extremely life-threatening situation and residents in those areas should follow advice given by local officials and evacuate immediately if told to do so. 3. Devastating hurricane-force winds are expected along portions of the west coast of Florida, where a Hurricane Warning is in effect. Milton is forecast to remain a hurricane as it crosses the Florida Peninsula and life-threatening hurricane-force winds, especially in gusts, are expected to spread inland across the peninsula. Preparations to protect life and property in the warning areas should be complete by tonight. 4. Areas of heavy rainfall will continue to impact portions of Florida well ahead of Milton through early Thursday. This rainfall brings the risk of life-threatening flash, urban and aerial flooding along with moderate to major river flooding. Flooding will be exacerbated in areas where coastal and inland flooding combine to increase the overall threat. FORECAST POSITIONS AND MAX WINDS INIT 08/0900Z 22.3N 88.9W 135 KT 155 MPH 12H 08/1800Z 22.9N 87.5W 140 KT 160 MPH 24H 09/0600Z 24.2N 85.8W 135 KT 155 MPH 36H 09/1800Z 26.0N 84.2W 125 KT 145 MPH 48H 10/0600Z 27.6N 82.6W 110 KT 125 MPH...NEAR THE COAST 60H 10/1800Z 28.8N 79.9W 70 KT 80 MPH...OVER WATER 72H 11/0600Z 29.7N 76.5W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 12/0600Z 30.4N 69.9W 45 KT 50 MPH...POST-TROP/EXTRATROP 120H 13/0600Z 31.5N 63.8W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Cangialosi