The National Weather Service on Saturday declared a flash flood watch for the Baltimore region through Sunday morning.
Widespread showers and thunderstorms were expected to develop Saturday night and into Sunday morning.
The heavy rainfall could measure between 1 to 4 inches.
“Heavy rainfall in short periods of time may cause creeks and streams to rapidly rise out of their banks along with the potential for flash flooding in urban areas,” the National Weather Service stated in an alert. “Flash flooding is a very dangerous situation.”
The areas included in the alert are Anne Arundel, Carroll Baltimore, Harford and Howard counties and Baltimore City. Other areas in Maryland included Montgomery and Prince George's counties.
Severe thunderstorms popped up Friday afternoon along the Appalachians of Maryland, Virginia and West Virginia.
A severe thunderstorm watch was in effect across Western Maryland and into Frederick County until 10 p.m.
Allegany, Washington and Frederick counties were also under a flash flood watch through midnight.
Sunshine is forecast Monday and for the early part of next week.