The good news this morning is that Matthew's heaviest winds - on the right side of the storm - have stayed offshore, sparing South Florida from the worst effects. That said, we won't know the full extent of the damage until the sun comes up, and survey crews can get some aerial views.
The projected track keeps Matthew very near - but hopefully just off - the Florida coast.
A slight westward shift would make a huge difference in the amount of damage Matthew could cause, and so no one is discounting the storm.
The Key messages from the 5am advisory read:
1. Matthew is likely to produce devastating impacts from storm surge, extreme winds, and heavy rains along extensive portions of the east-central and northeast coast of Florida today.
2. Evacuations are not just a coastal event. Strong winds will occur well inland from the coast, and residents of mobile
homes under evacuation orders are urged to heed those orders.
3. Hurricane winds increase very rapidly with height, and residents of high-rise buildings are at particular risk of strong winds. Winds at the top of a 30-story building will average one Saffir-Simpson category higher than the winds near the surface.
4. When a hurricane is forecast to take a track roughly parallel to a coastline, as Matthew is forecast to do from Florida through South Carolina, it becomes very difficult to specify impacts at any one location. Only a small deviation of the track to the left of the NHC forecast could bring the core of a major hurricane onshore within the hurricane warning area in Florida and Georgia. Modest deviations to the right could keep much of the hurricane-force winds offshore. Similarly large variations in impacts are possible in the hurricane watch and warning areas in northeast Georgia and South Carolina.
5. The National Hurricane Center is issuing Potential Storm Surge Flooding Maps, and Prototype Storm Surge Watch/Warning Graphics for Matthew. It is important to remember that the Potential Storm Surge Flooding Map does not represent a forecast of expected inundation, but rather depicts a reasonable worst-case scenario -- the amount of inundation that has a 10 percent chance of being exceeded.
FORECAST POSITIONS AND MAX WINDS
INIT 07/0900Z 28.2N 80.0W 105 KT 120 MPH
12H 07/1800Z 29.6N 80.6W 100 KT 115 MPH
24H 08/0600Z 31.5N 80.5W 90 KT 105 MPH
36H 08/1800Z 32.6N 79.2W 80 KT 90 MPH
48H 09/0600Z 33.1N 77.7W 65 KT 75 MPH
72H 10/0600Z 31.5N 74.5W 50 KT 60 MPH
96H 11/0600Z 29.0N 75.0W 40 KT 45 MPH
120H 12/0600Z 27.0N 76.5W 35 KT 40 MPH