Heavy rain in Maryland prompted the evacuation of at least one elementary school and dozens of water rescues on Tuesday, as a slow-moving storm system threatened to bring the risk of flash floods to the Mid-Atlantic, the authorities said.
The Georges Creek region, which surrounds a tributary stream of the North Branch Potomac River in western Maryland, was most affected, approaching record water levels for the area. Several major roads in Allegany County were impassable by midafternoon, the sheriff’s office there reported. Parked cars began to float on the street in Westernport, Md., a town along the creek, as floodwaters inundated the ground floors of homes and businesses in the downtown area.
The National Weather Service had issued flash flood warnings for parts of western Maryland and West Virginia on Tuesday afternoon.
The Weather Prediction Center has issued a Level 2 out of 4 risk for excessive rainfall, potentially leading to flash flooding across eastern North Carolina, eastern Virginia, Maryland, eastern West Virginia and extending into central and southern Pennsylvania through Wednesday.
In Allegany County, in northwestern Maryland, the heavy rain forced officials to dismiss classes early, to cancel all after-school activities and suspend busing for the afternoon.
Rising floodwaters on Tuesday afternoon forced emergency crews to evacuate students and staff members at Westernport Elementary School, according to school officials.
Water levels breached the second floor, according to Kati Kenney, a county spokeswoman, who said it took about 15 boat trips to rescue the about 150 students and 50 adults inside by 4:30 p.m. Three neighboring counties assisted in the water rescues, she noted. Officials said no injuries were reported.
“We’ve handled maybe 20, 25 rescues at this point,” Jonathan Dayton of Potomac Fire Company No. 2, the volunteer fire department of Westernport that moved the students to higher ground, said after 5 p.m. “There’s been incidents all day long.”
Mr. Dayton added that most of the 911 calls the department handled were for people trapped in their homes. Several hundred residents who live in the downtown area of Westernport, a town of about 1,800 residents, were also asked to evacuate.
No other schools were flooded, Ms. Kenney said, but students at other schools who could not be safely dismissed were staying at the school with employees until they could leave safely.
Students at George’s Creek Elementary School in Lonaconing, Md., were transported to a school in Frostburg, Md., on higher ground, according to the county school district.
In Keyser, W.Va., a small city of about 5,000 residents about five miles from Westernport, rescue workers handled “a small number” of water rescues, according to Luke McKenzie, director of Mineral County’s emergency services.
Rising floodwaters prompted evacuation orders for several streets in Keyser, which lies on the North Branch of the Potomac River, affecting hundreds of residents.
“As long as we don’t get any more heavy bands” of rainfall, Mr. McKenzie said, “we’re not expecting much more damage.”
Forecasters expressed concern for areas where the ground is especially vulnerable in North Carolina. David Roth, a meteorologist at the Weather Prediction Center, said the state has been particularly at risk since Hurricane Helene.
“Helene just made everything worse,” he said. “There were some landslides in western North Carolina from it. It takes a while to recover from a tropical cyclone. So their ground is more sensitive.”
Mr. Roth said North Carolina’s complex terrain was another factor of concern.
“They have a lot of up and down variation,” he said. “Even without Helene, almost every time it rains moderately, to have the mountains, basically you get these small waterfalls.”
The Weather Prediction Center also noted that the hills and mountains stretching from southern Pennsylvania through Virginia could receive additional rainfall because of the way the air is being pushed up the slopes. Recent rainfall has saturated the ground in this region, further elevating the risk of flash flooding.
The storm has brought repeated rounds of heavy rain to the Southeast since last week. Its slow-moving nature and a continuous feed of moisture from the Gulf and Atlantic are the main risk factors for flash floods.
Forecasters have called this an atmospheric river, a term more commonly associated with the steady streams of moisture that soak the West Coast but that also describes patterns responsible for rain in the East.
The system is expected to reach the Great Lakes by Wednesday, when thunderstorms will most likely become more scattered and less intense. However, a lower-level risk for flash flooding, 1 out of 4, was expected across parts of the Carolinas and into southern Pennsylvania until Thursday morning.
Judson Jones contributed reporting.
