I'm of course still preoccupied with the bad weather along the U.S. southeast coast. All I can do is look at weather sites on the internet (accuweather.com, weather.com, etc.) and try to understand what is happening and what might happen next. My home town, Morehead City (pop. 8,000) in North Carolina, is at the northern end of Matthew's path, they are saying, and therefore is less at risk than other cities and towns. Right now, it's about 1 a.m. over there.
Above is a map I grabbed off weather.com a few minutes ago. You can see the storm sitting off the Georgia and South Carolina coasts, between the beautiful old cities of Savannah (metro pop. 375,000) and Charleston (metro pop. 740,000). I hope a lot of people have left those areas and moved westward to get out of the way. For scale, the distance from Savannah to Morehead City is about 400 miles (650 km) — a 6½ hour journey by car.
This is a very low coastline of mudflats, salt marshes, sandy beaches, and wide estuaries. It's called "the low country" in South Carolina. If the winds push water up against it, as they will likely do, the flooding from the storm surge might be disastrous. And that's especially true if the worst of the storm's winds arrive at high tide. Much of Charleston, for example, is at sea level, and the highest points in the town are only 20 feet above sea level. Morehead City is even lower — 0 to 16 feet (5 m) of elevation.
Look at the rainfall totals! Five to fifteen inches of rain (between 125 mm and 400) will fall in just a few hours. Right along the coast, the rain might not be a big problem, but 50 miles inland, where there are hills and valleys and a lot of small and larger rivers, flooding can be catastrophic. Eastern N.C. has already had significant rain and some flooding over the past few weeks.