Meteorologists warned Marylanders to stay on guard for flooding into this weekend, with rivers swollen and little respite from the rain in the forecast.

While precipitation slowed Friday afternoon, the National Weather Service warned on Twitter: “The relative lull in the rainfall will be ending this evening as rain returns to the area. At a minimum, this will exacerbate ongoing flooding.”


The wet and stormy weather pattern that has dominated this week already caused major flooding and damaged roads in Frederick County, and with more precipitation forecast through Saturday, meteorologists on Friday also warned the Potomac River will hit soon hit flood stage, and remain flooded through Monday.

A flood watch was put in effect Saturday morning until 8 p.m. for most of the state, with additional rainfall of 3 inches to 5 inches expected in Southern Maryland and 1 inch to 3 inches predicted elsewhere, according to the National Weather Service. Flash floods are possible, and the weather service warned small streams and low-lying areas are especially at risk for floods. Ground already saturated with rainwater could cause increased risk of flooding, the weather service warns.

Flood warnings were issued across Southern Maryland on Friday as streams overflowed their banks and continued to rise. The St. Mary’s River quickly hit flood stage Friday morning, and road closures were widespread across St. Mary’s, Calvert and Charles counties.

Rain has been intermittently falling across Maryland since Sunday, and it’s expected to continue through Saturday and resume next week. More than 4 inches of rain had fallen from Sunday through Thursday at Baltimore-Washington International Thurgood Marshall Airport, the Baltimore region’s point of record.

An emergency declaration remains in place in the city of Frederick indefinitely. Officials were urging Frederick residents to conserve water to relieve a wastewater treatment plant overburdened by the heavy rains.

Severe thunderstorms Tuesday night caused intense flooding in Frederick County, where the National Weather Service estimated rain fell at 4.3 inches per hour and precipitation totaled up to 6.5 inches in some areas. Frederick Mayor Michael O’Connor issued an executive order Wednesday declaring a state of emergency to allow the city access to state and federal funding to assist with recovery.

“The state of emergency is an administrative tool,” Frederick County Executive Jan Gardner said. Gardner compared the rainfall to a 16-hour storm that caused historic flooding of Carroll Creek in 1976. “We are not restricting travel or asking residents to do anything immediately other than to make sure they use extreme caution during this time period.”

In Frederick County, floods stranded a MARC train Tuesday night with 85 passengers on board and resulted in about 60 water rescues.

The MARC train’s Brunswick line continued to operate on a modified schedule Friday because of damage on the rail lines caused by weather, the Maryland Transit Administration said. There was no service Friday at the Martinsburg, Duffields, Harpers Ferry or Brunswick stations, and limited service at Point of Rocks. The metro is honoring Brunswick line tickets.

Various roads have been closed due to flooding and debris.

The city also advised staying clear of Carroll Creek near its confluence with the Monocacy River because of potential sewer overflows. The Monocacy was expected to reach flood stage, 15 feet, by Thursday afternoon and crest near 17.7 feet by Saturday afternoon.

The Potomac is expected to hit flood stage Friday night, crest near 17.8 feet Sunday morning and remain flooded through Monday morning. Flood warnings are in place until then along the Potomac from Washington County to Washington, D.C.

Frederick residents have been asked to refrain from using water to wash dishes or clothes because of burdens on the city’s wastewater treatment plant, which is at risk of overflowing.

“The massive amount of rain simply has overwhelmed already stressed drainage systems, sewage systems and stormwater ponds,” Gardner said.


Frederick’s state of emergency will stay in effect until it is lifted by executive order.

Extensive rainfall is expected to continue Wednesday night into Thursday, with the heaviest downpours beginning Thursday evening into Friday morning.

The forecast calls for rain every day for the next week, she added.

The Frederick County fire department responded to 31 calls for water rescues, resulting in 75 people being removed from vehicles that have been stranded, disabled or washed from the roadway, said fire chief Tom Owens. While there has been no loss of life so far, the chief urged residents to be extremely careful and not travel unless necessary.

“It's a basic precaution in these weather conditions that we hope our citizens are going to heed, and if you have to travel, never drive through water levels — particularly if you can't see the road surface,” Owens said. “Take that as a sign that that road in front of you may not be there.”

Frederick spokeswoman Patti Mullins said many homes across town had flooded basements but that she wasn't aware of any residents who had been displaced.

The city does not yet have a damage estimate, Mullins said.

The Associated Press and Baltimore Sun reporters Scott Dance and Christina Tkacik contributed to this article.