Matthew is the strongest hurricane to hit the US since

[malaise]

48. Latest from Jeff Masters -With or Without a Landfall, Category 4 Matthew Will Pose an Extreme Threat

https://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=3469
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NHC’s Hurricane Warning as of 8 pm extended from Boca Raton, FL, to South Santee River, SC, including Lake Okeechobee and Orlando. As of 8 pm EDT, Matthew was moving toward the northwest, but slightly more northward than westward, at about 13 mph. Given that Matthew was then located about 75 miles east of Palm Beach, we can be confident that Matthew will not make landfall south of Palm Beach. (A reminder: NHC defines landfall as the center of a tropical cyclone reaching the coast. A hurricane’s eyewall can move along the coast without it being considered landfall of the storm itself.)

Matthew’s path should undergo a very gradual rightward arc as it approaches the angled Florida coast, which makes it very difficult to say exactly where landfall might occur. The more important question may be where Matthew’s strongest winds come ashore. Especially if Matthew undergoes an ERC, parts of its eyewall could affect the entire coastline from around Palm Beach north to the Georgia coast for extended periods, although these winds may only be around Category 1 strength. A broader field of sustained winds above tropical-storm strength (39 mph) can be expected well inland, including Lake Okeechobee and the Orlando area. As we discussed in our our post on Wednesday morning, the most likely point for landfall--if landfall occurs--is Cape Canaveral, which juts about 10-15 miles into the Atlantic.

Extreme storm surge possible in northern Florida, Georgia, and South Carolina
Even a broader, weaker Matthew would retain its ability to produce severe storm surge north of its path, especially along Florida’s First Coast (including St. Augustine and Jacksonville) and the coast of Georgia. As of late Thursday afternoon, the entire coast from near Boca Raton, FL, to Cat Island, SC, was under a storm surge warning under a prototype NHC system expected to become operational next year. As Matthew churns northward, the northeast winds ahead of it will pile water against the coastline, leading to what could be record or near-record storm surges in some areas.