Monitoring Reports

There was no significant rainfall in the Potomac River basin over the past 24 hours, and flows at both Point of Rocks and Little Falls continue to fall. Scattered showers and thunderstorms are expected throughout the basin for the next several days. The Mid-Atlantic River Forecasting Center quantitative precipitation forecasts (qpfs) indicate that most of the basin will receive up to 1/4 inch of rain over the next 48 hours and between 1/4 to 3/4 inches over the next 5 days.

Flows at Point of Rocks and Little Falls continue to fall. Most of the basin received little or no rain over the last 24 hours, though accumulations of up to 0.25 inches were reported in a few locations. According to National Weather Service (NWS) forecasts, there is a chance of showers and thunderstorms throughout the Potomac basin both today and tomorrow. However, the Mid-Atlantic River Forecasting Center quantitative precipitation forecasts (qpfs) indicate accumulations of only trace amounts over the next 48 hours.

Little Falls flow is falling from yesterday's higher daily average and is currently at 1480 cfs. Yesterday, the basin received little or no rain. There is a chance of thunderstorms this weekend, and the National Weather Service (NWS) quantitative precipitation forecasts (qpf) indicate that the majority of the basin may receive from 0.01 to 0.5 inch of rain over the next 48 hours.

Yesterday's storms resulted in accumulations of over a half inch of rain in certain localized areas of the basin near the Washington metropolitan area, causing flow at Little Falls to rise slightly. However, most upstream areas of the basin received little or no rain. There is a chance of thunderstorms this weekend, and the National Weather Service (NWS) quantitative precipitation forecasts (qpf) indicate that the majority of the basin may receive from 1/4 to 1 inch of rain over the next 48 hours.

Flow at Point of Rocks is currently 1,660 cfs (1,070 MGD). For the most part, the basin received no rain yesterday. Approximately 0.10 inches were seen in limited western portions of the basin. The National Weather Service (NWS) quantitative precipitation forecasts (qpf) indicate that the majority of the basin will receive 0.0 to 0.1 inches of accumulated rain over the next 5 days.

Flow at Point of Rocks is currently 1,800 cfs (1,160 MGD). In the past 7 days, the basin has received 0.5 inches of rain with minimal rain accumulation occurring for yesterday. The National Weather Service (NWS) quantitative precipitation forecast (qpf) indicates that 0 to 0.25 inches of rain may occur over the next 5 days.

The flow at Point of Rocks is currently above 2,000 cfs and it appears that flow is going to stay above that level for at least a week. Daily monitoring is discontinued until flows drop below the 2,000 cfs threshold. The Washington D.C. area and the eastern portion of the Basin received precipitation totals between 0.5 to 2 inches. However, most of the Basin, particularly in the western portion, received precipitation totals of 0 to 0.1 inches.

Flows in the basin have increased due to the recent precipitation. The National Weather Service forecasts accumulations of 0.5 to 1.5 inches of rain throughout the basin over the next 5 days.

Flow at Little Falls is currently 1520 cfs (980 MGD). The MARFC observed precipitation map shows that much of the western part of the basin received 0.05 to 1 inch of rain in the past 24 hrs. The National Weather Service (NWS) quantitative precipitation forecasts (qpf) indicate a chance of 0.75 to 3.2 inches of accumulated rain across the basin over the next 5 days. Today 0.25 to 0.5 inches of rain is expected for the Washington, D.C. area.

Stream flows continue to fall throughout the basin. Yesterday's daily mean flow at Little Falls was 890 MGD (1370 cfs). The July 4th whitewater release is almost past Point of Rocks, and should be arriving at Little Falls today - producing a short-term uptick in flow.

MARFC's observed precipitation maps indicate that there were scattered thunderstorms in the basin over the past 24 hours, with accumulations
of 1/2 to 1.5 inches in a few localized areas. MARFC predicts accumulations of over an inch throughout much of the basin in the next 48 hours.