Monitoring Reports

Light rain is forecast in the Potomac basin over the next three days, with accumulations of up to 0.25 inches predicted for some areas. Longer range forecasts indicate heavier rain – with accumulations of about an inch - 6 and 7 days in the future. 

Recent basin-wide average precipitation (above Little Falls):
(based on CO-OP's Low Flow Forecast System analysis of Middle Atlantic River Forecast Center (MARFC) gridded multisensor precipitation estimates)

River flow at Point of Rocks continues to track close to CO-OP’s daily monitoring threshold of 2000 cfs and is expected to for the next couple of days. The basin received no precipitation yesterday. Precipitation forecast totals are between 0.01 and 0.1 inches for the next three days.

River flow at Point of Rocks is expected to remain close to CO-OP’s daily monitoring threshold, 2000 cfs, for the next several days. The basin received negligible precipitation yesterday. Precipitation totals between 0.0 and 0.1 inches are forecast for the next three days.

River flow at Point of Rocks is expected to remain close to CO-OP’s daily monitoring threshold, 2000 cfs, for the next several days. The basin received negligible precipitation yesterday. Precipitation totals between 0.01 and 0.1 inches are forecast for the next three days.

River flow at Point of Rocks is expected to remain close to CO-OP’s daily monitoring threshold, 2000 cfs, for the next several days. The basin received negligible precipitation yesterday and no rain is forecast during the next three days.

Most parts of the Potomac basin above Little Falls received 1/10 to ½ inch of rain yesterday. River flows are already responding. However, the forecast is for dry conditions over the next 7 days, so we expect this slight increase in flows to be short-lived.

Daily flows:
Little Falls gage flow 2022-10-31: 1196 MGD (1850 cfs)
Little Falls gage flow 2022-11-01: 1209 MGD (est., based on recently available real-time data) (1870 cfs)

Over the past day, 0 to 0.1 inches of precipitation occurred in the Potomac basin above Little Falls; the majority occurred in the North Branch. According to the MARFC’s 72-hour forecast, total rainfall in the basin will range from 0.01 to 0.5 inches over the next three days, with more rain occurring in the southeastern portions (including the DC area) than in the northwestern parts.

Daily Potomac flow and demand update (Sunday, 2022-10-30)
Over the past day, no significant rainfall occurred in the Potomac basin above Little Falls. According to the MARFC’s 72-hour forecast, total precipitation in the basin will range from 0.01 to 0.25 inches over the next three days, with more rain occurring in the southeastern portions (including the DC area) than in the northwestern portions.

No significant rainfall occurred in the Potomac basin above Little Falls over the past day. According to the MARFC’s 72-hour forecast, total precipitation in the basin will range from 0.01 to 0.25 inches over the next three days, with more rain occurring in the southeastern portions of the basin (including the DC area) than in the northwestern portions.

Recent basin-wide average precipitation (above Little Falls):

Stream flows in the Potomac basin continue to slowly decline. According to the National Weather Service’s 7-day cumulative precipitation forecast, little rain is expected over the next week. There was a data gap in real-time flow at the USGS’s Point of Rocks gage yesterday, so yesterday’s daily average flow is estimated