Monitoring Reports

No precipitation fell in the Potomac basin over the past 24 hours. The National Weather Service predicts little rain over its 5-day forecast period, but the trajectory of Hurricane Earl is uncertain, and it could have an impact on the basin. Last weekend's AVF water quality release from Jennings Randolph Reservoir should be arriving at Little Falls on Friday. Note: yesterday's daily mean flow values are not available for many Potomac basin gages, including Point of Rocks and Little Falls, so values given below for 8/30 are estimated from available real-time data.

Flows from the Shenandoah River and last weekend's artificially varied flow release should help to maintain flows at Point of Rocks and Little Falls over the next couple of days. No significant precipitation fell in the basin yesterday, and the National Weather Service predicts no rain over the 48-hour forecast period. There is a possibility of between 0.01 and 0.10 inches of rain over the 5-day forecast period.

Flows in most Potomac basin tributaries are slowly dropping, but recent rain events have increased flow in the Shenandoah River, and this should help to maintain flows at Point of Rocks and Little Falls over the next several days. No significant precipitation fell in the basin yesterday, and the National Weather Service predicts no rain over its 5-day forecast period. The US Army Corps of Engineers initiated a 24-hr 870 cfs AVF (Artificially Varied Flow) release from Jennings Randolph Reservoir yesterday morning.

Aqueduct withdrawals at the Little Falls intake caused a drop in flows at the Little Falls gage; flows should recover sometime later today. Flows at the Point of Rocks gage remain steady. An artificially varied flow is scheduled to be released from Jennings Randolph Reservoir today and should temporarily raise flows during the next couple of days.

Flow at the Point of Rocks gage increased slightly over night due to small amounts of rain in the area. Trace amounts of precipitation were seen yesterday in an area reaching from Jefferson County, WV to downstream of the Washington metro area and over a small portion of the South Fork Shenandoah River. Both the 48-hour forecast from the River Forecast Center and the 5-day National Weather Service QPF are predicting no accumulated precipitation over their respective forecast periods in the Potomac basin.

The Middle Atlantic River Forecast Center shows that some portions of the Basin received rain accumulations of up to a 0.01 of an inch yesterday; most areas received no rain. The Forecast Center shows no rain over the next 48 hours. The National Weather Service Quantitative Precipitation Forecast shows no rain in the basin above Little Falls over the next 5 day period.

Flows at Point of Rocks rose slightly due to small showers above the
gage. Flows at Little Falls continue to drop.

Potomac River flow at Little Falls increased slightly from yesterday. Over the past 48 hours, portions of the Potomac Basin received between 0 and a 1/4 inch of rain; some isolated areas received up to 1/2 an inch of rain. The Middle Atlantic River Forecast Center predicts that scattered showers may occur through Wednesday evening. The 48-hour QPF shows possible rain accumulations between 0 and a 1/4 inch of rain with larger amounts occurring in the upper portions of the basin.

The Middle Atlantic River Forecast Center shows that most of the basin received between 0 and 0.5 inches of rain yesterday. A few isolated areas near the North Fork of the Shenandoah River received as much as 4 inches of rain yesterday. Over the next 48 hours there is a chance of 0.10 to 1 inches of rain, with larger amounts occurring in the southwest portion of the basin. The National Weather Service Quantitative Precipitation Forecast shows possible accumulation of 0 to 0.5 inches of rain over the next 5 day period.

Potomac River flow at Little Falls continues to drop while flow at Point of Rocks remains relatively steady. Over the past 24 hours, the portion of the Potomac Basin below the confluence of the North and South Branches of the Potomac River received between a 1/10 and 1 inches of rain; a small area near the North Branch reservoirs received a 1/10 of an inch of rain.

Potomac River flow at Little Falls has been steadily dropping over the past several days, as the effect of the recent local storms recedes. Over the past 24 hours, watersheds in the northern-most portion of the Potomac basin received between a 1/10 and 1/2 inches of rain, and a slight uptick in flows can be observed in streams in the Potomac North Branch sub-basin. The Middle Atlantic River Forecast Center predicts that showers and thunderstorms from a passing cold front will result in accumulations of between 1/10 and 1/4 inches of rain in most of the basin over the next 48 hours.