The 3-day forecast (MARFC) estimates 0.01 to 0.1 inches of rainfall in most of the Potomac Basin. There is a chance that the North Branch may receive up to 0.5 an inch of rainfall. According to our recent basin-wide average precipitation, the basin received 0.03 inches of rain in the past 24 hours. The Little Falls gage is now reporting. The gage antenna had been blocked by a broken-down crane.
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)
Yesterday's area-weighted average basin precipitation: 0.03 (inches)
Past 3-day cumulative area-weighted average basin precipitation: 0.13 (inches)
Past 7-day cumulative area-weighted average basin precipitation: 0.14 (inches)
Daily flows:
Little Falls gage flow 2021-07-28: 1732 MGD (2680 cfs)
Little Falls gage flow 2021-07-29: 1583 MGD (est., based on recently available real-time data) (2450 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2021-07-28: 1196 MGD (1850 cfs)
Point of Rocks flow 2021-07-29: 1202 MGD (est., based on recently available real-time data) (1860 cfs)
Yesterday's Washington metropolitan area Potomac River withdrawals and discharges (2021-07-28):
Fairfax Water Corbalis withdrawal (Potomac): 138 MGD
WSSC Water Potomac withdrawal: 136 MGD
Washington Aqueduct withdrawal: 150 MGD - revised 7/30/21 from 131 MGD
Loudoun Water withdrawal: 12 MGD
Loudoun Water Broad Run discharge: 3 MGD
Total Potomac withdrawal: 418 MGD
Total net Potomac withdrawal: 415 MGD
Loudoun Water drought operations protocol river flow values (1627562024):
QPR: 1850 cfs
QPR, obs: 1850 cfs
QPR, WS: 0 cfs