Grab your umbrellas and raincoats: the post-Labor Day work week is off to a flying start and there’s a threat of flooding.

Storm Team4 has declared a weather alert for rain, as well as flood watches and warnings in the DC area.

A flood warning will be in effect until 11:30 a.m. for parts of Montgomery and Frederick County, Maryland, following heavy rainfall. A warning means that flooding is imminent or in progress.

A flood watch will be in effect until 2 p.m. Tuesday for areas such as Washington, DC; Montgomery and Prince George counties in Maryland; Alexandria, Falls Church, Arlington County and Loudoun County in Virginia. Be prepared for dangerous weather conditions. Here is a complete list of weather alerts.

Remember: never drive on a flooded road. Turn around, don’t drown.

“It’s not an all-day event, but it is a hard-hitting event during the morning hours,” said Somara Theodore, meteorologist for Storm Team4.

Tuesday rainfall schedule and potential totals

More waves of rain are expected to roll into the DC area Tuesday morning. Storm Team4 radar shows areas of steady moderate rain moving west to east until around 9am

Showers could drop 1 to 3 inches of rain, but amounts up to 4 inches are possible in isolated locations, according to the National Weather Service.

Skies will likely begin to clear around lunchtime, although spotty showers may continue in areas north and west of DC into the evening. The highs will reach the low 80s.

Storm Team4 is tracking more intermittent showers through Wednesday.

Partially sunny skies are expected to return by Thursday.

Stay with Storm Team4 for the latest predictions. Download the NBC Washington app at iOS and android to receive severe weather alerts on your phone.