No appreciable rain fell in the basin over the past 24 hours; a trace to 0.25 inches is expected over the next three days.
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 multi-sensor precipitation estimates)
Yesterday's area-weighted average basin precipitation: 0 (inches)
Past 3-day cumulative area-weighted average basin precipitation: 0.31 (inches)
Past 7-day cumulative area-weighted average basin precipitation: 0.45 (inches)
Daily flows:
Little Falls gage flow 2021-07-31: 1480 MGD (2290 cfs)
Little Falls gage flow 2021-08-01: 1519 MGD (est., based on recently available real time data) (2350 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2021-07-31: 1150 MGD (1780 cfs)
Point of Rocks flow 2021-08-01: 1150 MGD (est., based on recently available real time data) (1780 cfs)
Yesterday's Washington metropolitan area Potomac River withdrawals and discharges (2021-07-31):
Fairfax Water Corbalis withdrawal (Potomac): 111 MGD
WSSC Water Potomac withdrawal: 129 MGD
Washington Aqueduct withdrawal: 121 MGD
Loudoun Water withdrawal: 11 MGD
Loudoun Water Broad Run discharge: 5 MGD
Total Potomac withdrawal: 372 MGD
Total net Potomac withdrawal: 367 MGD
Loudoun Water drought operations protocol river flow values, based on yesterday’s flows:
QPR: 1780 cfs
QPR, obs: 1780 cfs
QPR, WS: 0 cfs
Note to Loudoun Water: See NWS ensemble flow forecasts (HEFS, GEFS, NAEFS) for Point of Rocks flow for the next 7 days – see https://www.weather.gov/erh/mmefs_marfc?id=PORM2&model=NAEFS.