Tropical Depression Florence, downgraded from a tropical storm, is transitioning to a nontropical weather system but is still dumping tremendous amounts of rainfall over North Carolina. As the historic rains and flooding only very slowly ease along the North Carolina coast through Sunday night, serious flooding is predicted to spread farther inland.
The National Weather Service warned of a “catastrophic, life-threatening flash flooding risk” in much of North Carolina, northern South Carolina and southwest Virginia on Sunday.
As excessive rainfall swept over west central North Carolina Sunday afternoon, the Weather Service declared a flash flood emergency for parts of the Charlotte area, this most severe type of flood alert. “This is an incredibly serious situation,” it tweeted. “Do NOT attempt to travel unless you are fleeing an area subject to flooding or under an evacuation order.”
The Weather Service said some bodies of water were rising to record levels in South Charlotte and that the extent of the flood impacts “may be unprecedented in some locations."
By Sunday evening, flash flood warnings extended from roughly Myrtle Beach to Roanoke.
By Monday and Tuesday, the torrents are expected to lift north through West Virginia and western Virginia before finally exiting the Northeast by Wednesday.
The floodwaters are expected to push many rivers to all-time highs and, toward the mountains of western North Carolina and southwestern Virginia, could spur life-threatening landslides.
“[A]reas of the North Carolina Piedmont and the mountainous terrain of western North Carolina will experience devastating flash flooding unlike anything in recent memory,” tweeted Greg Carbin, chief of the operations branch at the National Weather Service. “Roads and bridges will wash away and damage will be severe.”
The threat of Excessive Rainfall continues in the Mid-Atlantic from Florence. pic.twitter.com/b7JrTnxxRG
— NWS MARFC (@NWSMARFC) September 16, 2018
Ryan Maue, a meteorologist for weathermodels.com, calculated the storm will dump the equivalent of 18 trillion gallons of rain, enough to cover Texas in four inches of water and fill the Chesapeake Bay.
Rainfall so far
Through Sunday afternoon, numerous locations in southeast North Carolina had endured more than 20 inches of rain, with Onslow and Carteret counties being hit particularly hard. At least three locations in these counties appear to have broken the state record for tropical storm or hurricane rainfall, exceeding the 24.09 inches that fell near Wilmington during Hurricane Floyd in 1999:
- Swansboro: 33.89 inches
- Hoffman Forest: 29.48 inches
- Sunny Point: 27.44 inches
- Nature Conservancy: 27.12 inches
- Newport: 25.20 inches
The Swansboro total is the most for any tropical storm or hurricane north of Florida along the East Coast and represents a new two-day and three-day rainfall record for North Carolina.
In the past year, Florence marks the third tropical system to set a new state rainfall record after Hurricane Harvey in Texas and Hurricane Lane in Hawaii.
The rainfall from Florence also a new rainfall record for a tropical system in South Carolina. The town of Marion posted a preliminary total of 18.13 inches.
Some other notable rainfall totals in South Carolina and North Carolina include:
- Wilmington: 23.59 inches
- Lumberton: 21.51 inches
- New Bern: 16.65 inches
- Fayetteville: 12.33 inches
- North Myrtle Beach: 10.22 inches
- Florence: 6.82 inches
- Raleigh: 5.07 inches
- Charlotte: Around 7 inches
- Columbia: 2.54 inches
The rain from Florence in Wilmington pushed its 2018 rainfall total to 86.79 inches. “This smashes the previous yearly rainfall record of 83.65 inches set in 1877...with over 3 months to go,” the Weather Service tweeted.
These rains have resulted in “an incredible amount of road closures across eastern and central North Carolina,” the Weather Service office in Raleigh tweeted early Sunday. “It’s remarkable that large portions of interstate 95 and many other roads are closed.”
Sunday night forecast: Heaviest rain heads toward mountains
As the former hurricane continues to draw moisture from the Atlantic Ocean, the rain will not end Sunday in the hardest-hit areas of southeast North Carolina. The intensity of the rain shouldn’t be as extreme as it was Friday and Saturday, but downpours may not fully relent until some time Monday.
Even through Sunday evening, flash flood warnings stretched from northeast South Carolina to southwest Virginia.
The heaviest rain Sunday night will shift from central North Carolina to west central North Carolina and southwest Virginia.
The Weather Service predicts about 2 to 5 inches of additional rain in this zone and isolated amounts to 8 inches, on top of what has already fallen.
Monday and Tuesday: Stormy conditions push north through Appalachians into New England
On Sunday night, Florence’s remnants will finally be pulled north and, on Monday, it will unload very heavy rainfall in West Virginia and western Virginia, especially north of Roanoke and west of Charlottesville, where a flash flood watch is in effect.
The rain may be particularly heavy in the mountains, where there is an elevated risk of flash flooding. Two to four inches of rain is likely to fall in this zone in a relatively short time, with isolated amounts over six inches. As some of these areas have seen much above-normal rain since the spring and waterways are full, river flooding is a significant concern.
While the heaviest rainfall will focus west and southwest of the Interstate 95 corridor, waves of showers and storms are likely to sweep through cities from Richmond to Boston. Locally heavy rainfall is possible in this activity.
Monday night into Tuesday, areas from interior Pennsylvania through New England may experience a burst of heavy rainfall that quickly dispenses one to three inches. Particularly in Pennsylvania, which has seen excessive amounts of rain in recent months, localized flooding is possible.
North Carolina rivers: Water levels to rise for days, record flooding possible
Most of the rivers in northeast South Carolina and eastern North Carolina are experiencing moderate to major flooding, and, in some cases, many will continue rising well into next week as floodwaters from the interior flow downstream.
The Cape Fear River in Fayetteville, N.C., already at flood stage, is forecast to rise 30 additional feet by Tuesday. A mandatory evacuation is in place in this area.
The Cape Fear River has reached flood stage at Fayetteville this morning, with SIGNIFICANT rise still to come. This will be very dangerous flooding over the next few days. #HurricaneFlorence pic.twitter.com/IbuyGnm9J7
— NWS Raleigh (@NWSRaleigh) September 16, 2018
Water levels along the Lumber River in Lumberton are forecast to top the record level set during Hurricane Matthew just two years ago.
“River levels will continue to rise today [Sunday] and early this week,” the Weather Service tweeted. “If you live near a body of water, don’t let your guard down and follow local evacuation orders!”
