Monitoring Reports

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.

Yesterday there was negligible precipitation in Potomac basin. The Middle Atlantic River Forecast Center predicts up to an inch of rain in the North Branch watershed over the next two days and the National Weather Service 5-day Quantitative Precipitation Forecast indicates a chance of 1/4 to 1 inch of accumulated precipitation across the entire basin.

The Middle Atlantic River Forecast Center shows that there were a few isolated areas of rain yesterday that accumulated up to 0.10 inches of rain. Over the next 48 hours there is a chance of 0.10 inches of rain in the North Branch watershed according to the Forecast Center. The National Weather Service Quantitative Precipitation Forecast shows possible accumulation of 0.10 to 0.50 inches of rain across the basin over the next 5 day period.

There has been significant rainfall in the DC metropolitan area over the past couple of days, but only approximately 1/4 of an inch in the western portion of the Potomac River basin. The Middle Atlantic River Forecast Center predicts 1/10 to 1/2 of an inch across the southern half of the basin over the next 48 hours, including in the South Branch and Shenandoah areas. The 5-day Quantitative Precipitation Forecast indicates a chance of up to 1 inch of rain across the entire basin.

Significant rain fell in the southeastern portion of the Potomac River basin yesterday, with the heaviest accumulations occurring near the DC metropolitan area. More rain is expected today, and the Middle Atlantic River Forecast Center predicts between 1/4 to 3/4 of an inch in the southern basin, including the DC area and parts of the Shenandoah. Though the recent rainfall has caused Potomac River flow at Little Falls to increase significantly, flows remain low in many upstream tributaries.