The National Weather Service in Washington D.C. has issued a Flood Watch, effective from 3 PM this afternoon to 10 PM EDT this evening, across the District of Columbia and selected areas of Maryland, including Anne Arundel, Cecil, Central and Southeast Montgomery, Prince Georges, Southeast Harford and Southern Baltimore, as well as certain regions in northern Virginia, such as Arlington/Falls Church/Alexandria and Fairfax. The watch warns of the potential for flash flooding caused by excessive rainfall.

According to the forecast, there exists an 80% chance of precipitation today with the likelihood of scattered showers and thunderstorms developing into more sustained rainfall possibly accompanied by thunder after 4 PM. The conditions are ripe to quickly deteriorate; multiple thunderstorms rolling in are anticipated to be able, drop as much as 2 inches of rain per hour. Some localities could see totals of around 5 inches, especially if they are struck by successive thunderstorms.

Tonight, the chances of showers and thunderstorms sit at 80%, with new rainfall amounts projected to vary between a tenth and a quarter of an inch, although thunderstorms could lead to higher totals. Tomorrow forecasts a 40% chance of isolated showers and thunderstorms before 8 AM, followed by scattered showers between 8 AM and 11 AM, transitioning to scattered showers and thunderstorms again after 11 AM. The emphasis on preparedness surfaces as this deluge is both imminent and potentially severe.

The weather service has stressed the danger of "excessive runoff" which may result in flooding of " rivers, creeks, streams, and other low-lying and flood-prone locations." Urban areas are particularly at risk for flooding due to poor drainage systems. Spotter activation may be needed later today to accurately monitor the situation. Residents in the affected areas are advised to stay vigilant, monitor updates, and be ready to take immediate action should flash flood warnings be issued.