Potomac River flows continue to fall. National Weather Service forecasts indicate that no rain will fall in the basin 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 multisensor precipitation estimates)
Yesterday's area-weighted average basin precipitation: 0 (inches)
Past 3-day cumulative area-weighted average basin precipitation: 0.04 (inches)
Past 7-day cumulative area-weighted average basin precipitation: 0.64 (inches)
Daily flows:
Little Falls gage flow 2023-08-19: 808 MGD (1250 cfs)
Little Falls gage flow 2023-08-20: 737 MGD (est., based on recently available real-time data) (1140 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2023-08-19: 963 MGD (1490 cfs)
Point of Rocks flow 2023-08-20: 918 MGD (est., based on recently available real-time data) (1420 cfs)
Yesterday's Washington metropolitan area Potomac River withdrawals and discharges (2023-08-19):
Fairfax Water Corbalis withdrawal (Potomac): 115 MGD (provisional)
WSSC Water Potomac withdrawal: 144 MGD
Washington Aqueduct withdrawal: 131 MGD
Loudoun Water withdrawal: 14 MGD
Loudoun Water Broad Run discharge: 5 MGD
Total Potomac withdrawal: 404 MGD
Total net Potomac withdrawal: 399 MGD
Loudoun Water Potomac River (PR) flow values for drought operations protocol (based on yesterday's flows):
QPR: 1490 cfs
QPR, obs: 1490 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.