Forecasters cautioned of possible flash flooding and coastal flooding Tuesday and Wednesday, with a stretch of rainy weather setting in by late Monday.
The National Weather Service issued a flash flood watch for nearly all of Maryland west of the Chesapeake Bay, effective from Tuesday evening through late Wednesday night. The storm could bring a total of 3-5 inches, with potentially heavier amounts in some localized areas.
A coastal flood watch was meanwhile 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.
Clouds were beginning to move into the region Monday afternoon, expected to bring rain by the evening hours and continuing for the next few days.
About 2 inches of rain could fall Tuesday and another 3 inches could fall Wednesday, with chances for storms bringing heavy downpours starting late Tuesday and lasting through Wednesday.
Rain is expected to taper off by early Thursday morning.
About 4 inches of rain has fallen so far this month 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.