'Torrential rain' of 5 inches or more, flash floods expected from storms across Carolinas | Raleigh News & Observer

The Carolinas are expected to get a drenching this week as thunderstorms and heavy rain showers move in.

Those storms are expected to bring flooding, 50 mph wind gusts, frequent lightning, hail and other hazards, the National Weather Service said on Sunday.

On Monday, the weather service upgraded its forecast, issuing flash flood warnings and watches across the Carolinas and into Virginia, anticipating 4-6 inches of rain or more throughout much of the Carolinas.

Most of central and eastern North Carolina plus much of South Carolina were under a flash flood watch through late Tuesday night.

In a series of hazardous weather outlooks, the weather service forecast very heavy rain and local flooding, with strong storms reaching wind speeds of 50 mph and frequent lightning.

Periods of showers and thunderstorms from Monday through Saturday were expected to bring locally heavy rainfall that could cause flooding.

Most of the storms will begin in the afternoon and evening, the weather service said.

The storm system is the result of a deep upper low-pressure area lingering across the mid-Atlantic region, the weather service said.

A plume of tropical moisture was expected to remain across eastern parts of the Carolinas through mid-week while an upper level trough remains over the eastern U.S., creating heavy rain and thunderstorms with “torrential downpours through at least Tuesday.”

The Nation Weather Service office in Newport/Morehead City said eastern North Carolina could see as much as 6 inches of rain, especially in coastal areas.

North Carolina Emergency Management warned on Sunday that the heaviest rain was expected from Monday through Wednesday, with flash flooding a threat for southeast and central North Carolina on Monday and Tuesday.

Some parts of North Carolina had already gotten up to 4 inches of rain by Sunday, the weather service’s Raleigh office said.

Upstate South Carolina and the Columbia and Myrtle Beach areas’ greatest threats from storms this week will be deadly cloud-to-ground lightning, heavy rain and possibly damaging winds and large hail, the weather service said Sunday.

Ocean conditions were expected to be rough this week, with winds strengthening currents, the weather service said.

A moderate risk of rip currents was forecast up and down the coast of the Carolinas on Sunday.

“Longshore currents can sweep swimmers and surfers into rip currents, piers, jetties, and other hazardous areas. Often, if the longshore current is strong enough, it will sweep swimmers off their feet, making it difficult to return to shore,” the weather service said. “Caution should be used when in or near the water. Check with the lifeguards before entering the ocean for possible hazards you may be swept into.”