Hurricane Florence was clearly visible from the International Space Station on Monday, September 10, 2018 | Source: NASA

Each summer, scores of Scott Countians and East Tennesseans flock eastward on U.S. Hwy. 501 to Myrtle Beach.

Tuesday afternoon, lanes were reversed on U.S. 501 and three other South Carolina highways as residents of the coastal area fled from Hurricane Florence, a raging tropical cyclone that is expected to deliver a crippling blow to a large swath of the Mid-Atlantic Coast and inland areas today (Thursday) and tomorrow.

Florence’s growth from an ordinary tropical storm to a major hurricane had been well-forecasted since the cyclone originated from a strong tropical wave that emerged off the coast of Africa on August 30. By Monday, it was evident that the worst-case-scenario was becoming reality, as Florence exploded in strength from a Category 2 hurricane to a Category 4 storm with winds in excess of 130 mph. 

“Unfortunately, the models were right,” the National Weather Service’s National Hurricane Center said in a sternly-worded forecast discussion Monday evening. “Florence has rapidly intensified into an extremely dangerous hurricane.”

As he issued a mandatory evacuation order for the coastal region Monday afternoon, South Carolina Gov. Henry McMaster didn’t mince words.

“We’re in for a real episode here,” the governor said. “We are expecting more wind than we had with Hugo and more water than we had with Matthew.” 

Forecasters with the NHC said that the hurricane would near Category 5 in strength — which is at the top of the Saffir-Simpson hurricane wind scale — by Tuesday afternoon.

“None of the guidance suggest that Florence has peaked in intensity,” the NHC said.

The hurricane center warned that the life-threatening dangers associated with the storm were three-fold: first, life-threatening storm surge along the coast, followed by freshwater flooding both along the coast and further inland due to “a prolonged and exceptionally heavy rainfall event,” and damaging hurricane-force winds.

Meteorologists were not certain where Florence would wash ashore, but as of Monday evening landfall was generally expected to be somewhere between Myrtle Beach and North Carolina’s Outer Banks. If the storm makes landfall as a Category 4 in North Carolina, it will be the strongest hurricane on record to make landfall that far north.

Even as the computer models that meteorologists use to derive their forecasts converged on the idea that the hurricane will not make a northward turn away from land before reaching the United States, it became more evident that a growing area of high pressure north of the storm would cause the storm to slow down — perhaps even stalling — once it reaches the coast. That means that once rainfall begins late this week, it could continue into early next week, with flooding possible anywhere from the Appalachian Mountains to the Atlantic Coast. Some weather models have shown as much as 30-to-40 inches of rain falling across some areas of interior North Carolina, which would result in catastrophic flooding.

Along the Cumberland Plateau, where several inches of rain fell Sunday and early Monday as remnants of Tropical Storm Gordon interacted with a cold front that swept in from the northwest, Hurricane Florence was not expected to have much of an impact.

“Overall, it still looks like Florence’s effect on our weather will be benign,” forecasters at the National Weather Service’s Nashville forecast office said Monday afternoon. “We may see surface winds late this week and over the weekend pick up to between 10 and 15 mph during the day. However, with temperatures in the 80s, that should be more refreshing than anything.”

The deep moisture that was in place across the region earlier this week, remnant moisture of Gordon that was carried in by the cold front and then stranded as the frontal boundary stalled, was expected to retreat westward as Florence nears the U.S. coast, resulting in hot, dry weather for the Cumberland Plateau for much of the week.

If the storm tracks further west than anticipated, weather along the Cumberland Plateau could turn “a bit more showery and breezy,” the NWS said, “but for now things are looking pretty good for the Mid-State.” 

While the northern Cumberland Plateau is likely to remain dry, appreciable rainfall is possible for parts of East Tennessee. The National Weather Service’s Morristown office said Monday that three-to-four inches of rain are possible in upper East Tennessee, around the Tri-Cities, as a result of the hurricane.