Widespread flooding is possible Tuesday and Wednesday as a drenching storm system crosses the region after bringing severe weather and tornado threats to the Southeast.
The National Weather Service issued a flash flood watch for nearly all of Maryland west of the Chesapeake Bay, effective Tuesday evening through late Wednesday night. The storm could bring a total of 3 to 5 inches of rain, with potentially heavier amounts in some areas.
A coastal flood watch was in effect along the western shore of the bay, from Harford County down to St. Mary's County, with tides as much as 2 feet above normal. That could lead to moderate flooding at high tide, according to the weather service.
A large, slow-moving system of low pressure is bringing the moisture up from the Gulf of Mexico, and a warm front within it spawned deadly tornadoes across the south-central and southeastern United States.
The warm air was forecast to bring instability that could lead to severe weather in Maryland on Wednesday evening, though the strongest risk of storms and isolated tornadoes was expected in an area from Georgia to Virginia, according to the Storm Prediction Center.
By the time rain tapers off early Thursday morning, it could make for one of Baltimore's wettest Aprils on record.
About 4 inches of rain had fallen this month through Monday at Baltimore-Washington International Thurgood Marshall Airport, more than an inch above normal. The forecast suggests that total could double, or more, before the month ends.
Baltimore's wettest April on record occurred in 1889, with 8.7 inches measured. More than 7 inches of rain has fallen in Baltimore only five other times since then, most recently in 1952.
This year is off to a wet start, with more than 15 inches of precipitation (including both rain and the liquid equivalent of snowfall), nearly 3 inches more than normal.