No significant amount of rain has fallen in the Potomac basin over the past 3 days. Around midnight last night, flow in the Potomac River at Point of Rocks temporarily dropped below CO-OP's threshold for drought monitoring of 2,000 cfs. We will reassess the need for daily monitoring after today's expected rainfall. According to Middle Atlantic River Forecast Center estimates, 1.25 to 2.5 inches is expected throughout the basin in the next 7 days. Slightly smaller amounts of 0.5 to 1.25 inches is expected in the next 5 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 precip: 0 (inches)
Past 3-day cumulative area-weighted average basin precip: 0.00 (inches)
Past 7-day cumulative area-weighted average basin precip: 0.06 (inches)
Daily Flows:
Little Falls gage flow 2019-10-15: 1273 MGD (1970 cfs)
Little Falls gage flow 2019-10-16: 1312 MGD (est., based on recently available real time data) (2030 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.
Point of Rocks flow 2019-10-15: 1409 MGD (2180 cfs)
Point of Rocks flow 2019-10-16: 1325 MGD (est., based on recently available real time data) (2050 cfs)
Yesterday's Net Potomac withdrawal (2019-10-15):
FW Corbalis withdrawal (Potomac): 105 MGD
WSSC Potomac withdrawal: 175 MGD
Aqueduct withdrawal: 148 MGD
Loudoun withdrawal: 10 MGD
Total Potomac withdrawal: 438 MGD