Storms that caused 1-in-1,000 year flood event in Tennessee and Georgia move up Atlantic coast

A storm system that caused what the National Weather Service calls a catastrophic, 1,000-year flood along the Tennessee-Georgia state line moved up the Eastern Seaboard on Friday, prompting flood advisories in coastal areas from North Carolina to Massachusetts.In McCaysville, Georgia, and Copperhill, Tennessee, residents and crews spent Friday cleaning up alongside the Toccoa River. Rainfall across the surrounding mountain watershed measured 10.28 inches (26.1 cms) over a six-hour period and 11.19 inches (28.4 cms) over 12 hours into Thursday morning, according to the weather service in Atlanta.Some instances of extreme weather are referred to as 1,000-year events because they have a 0.1%, or 1 in 1,000, chance of happening in a particular place in any given year. While uncommon, “it’s definitely possible to have multiple 1,000-year events in the same year,” the weather service said.The Toccoa flows into the Ocoee River, where the Tennessee Valley Authority was managing high water leve