A slow-moving storm system is expected to fuel intense downpours of widespread showers and thunderstorms from Alabama to Florida and across the Carolinas, Virginia and West Virginia through Wednesday.

The storm is meandering its way over the Lower Mississippi Valley, pulling in a blend of warm, moist air from the Gulf of Mexico and the Atlantic into the Southeastern United States. “These slow-moving systems bring a lot of moisture up,” said Bryan Jackson, a meteorologist at the Weather Prediction Center. “They’re not moving much, so they tend to bring repeating rainfall to some of the same areas.”

Repeated rounds of heavy rain from this storm since last week have raised the risk of flash flooding in the region. On Sunday, the heaviest rainfall was focused over northern Florida and southern Georgia.Flooding was also a concern for parts of Alabama, northern Mississippi and the Carolinas, where the ground remains saturated from recent storms.

The system is forecast to bring further bouts of rainfall and thunderstorms across the Southeast and into parts of the Mid-Atlantic through Wednesday.

The Weather Prediction Center said that rainfall could be especially intense along the Southeast coast and in the mountainous regions. Urban areas along the coast of Virginia were also included in the flood outlook as they are especially prone to flooding during periods of heavy rain.

“We’re looking at a focus along the Blue Ridge, so that’s the eastern side of the Appalachians,” said Mr. Jackson. “Also, along the Carolina coast, up from Myrtle Beach and eastern North Carolina is another focused area for some significant rainfall.”

Farther south, forecasters were concerned for the Miami metro area, where the Weather Prediction Center issued a Level 3 out of 4 risk for flash flooding through Tuesday. Rainfall rates could exceed two inches per hour, with localized totals of three to seven inches, which may lead to significant flooding.


A Level 3 out of 4 “slight risk” for flash flooding was also issued from Virginia to the Florida Peninsula. Scattered storms were expected across parts of the Tennessee and Mississippi Valleys, where a Level 1 out of 4 risk is in place. Those areas have seen heavy rains recently, leaving the ground saturated and more prone to flooding.

The Raleigh, N.C., office of the Weather Service said it expected two to four inches of rain across central North Carolina, with the heaviest rainfall likely through Tuesday morning.

Flood watches had been issued for central and western North Carolina and for portions of western and southeastern Virginia through Tuesday.