Monitoring Reports

This is Day 1 of the annual Washington metropolitan area (WMA) drought exercise, which will be conducted on Wednesday, Nov 20 and Thursday, Nov 21. The exercise scenario appears below. During the exercise, WMA water suppliers are sending data on withdrawals and reservoir levels twice daily, and ICPRB CO-OP staff are communicating via phone with supplier operations staff regarding requested operational changes.

EXERCISE SCENARIO

Daily Monitoring was initiated on 9/23/2019 and discontinued on 10/23/2019.

River flow at Point of Rocks has been above our drought monitoring trigger of 2000 cfs for the past two days, and the Middle Atlantic River Forecast Center's streamflow forecasts indicate that flows will remain above this level for the next week. Therefore, daily monitoring will be discontinued until further notice. Thank you all for your contributions to the monitoring effort!

No rain fell in the basin over the past 24 hours according to the Middle Atlantic River Forecast Center. Over the next 7 days, between 1 and 1.75 inches of rain are expected in the basin.

Flows have been fluctuating around 2000 cfs, the threshold for daily monitoring. Daily monitoring will be continued until flows are consistently above the 2000 cfs threshold.

On average, the basin received less than half an inch of rainfall yesterday, with rainfall totals increasing from west to east. Far western areas of the basin received trace amounts of rain while rainfall totals exceeded 1.5 inches in parts of the DC metro area. Between 0.5 and 1.5 inches of additional rainfall is expected over the next 7 days.

According to the Middle Atlantic River Forecast Center (MARFC), 0.01 to 0.75 inches of precipitation fell in the basin over the last 24 hours (ending at 7:00 AM Sunday). It is currently raining and MARFC forecasts that 0.75 to 2.00 inches of precipitation will fall over the next 72 hours. The National Weather Service expects 1.25 to 3.00 inches of precipitation over the next 7 days.

According to the Middle Atlantic River Forecast Center, no rain fell in the basin over the past 24 hours. The National Weather Service expects up to an inch of rain in the basin over the next 7 days.

Flows at the USGS gage at Point of Rocks are currently above 2000 cfs, the trigger for daily monitoring. Please note, however, that the USGS has been working on some recent issues with the stage sensor at the Point of Rocks gage. Daily monitoring will be continued at this time to confirm that flows remain above the 2000 cfs threshold for a few days given recent gage corrections.

In the last 24 hours, trace amounts of precipitation fell in Washington County, Maryland. According to MARFC's precipitation departure calculations, last Wednesday's precipitation improved basin precipitation totals, which are now near normal for the month of October. Precipitation amounts between 0.5 and 0.75 are expected over the next 5 to 7 days.

Flow at the USGS gage at Point of Rocks is currently below 2000 cfs, the trigger for daily monitoring. Daily monitoring will be continued at this time. *

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

According to the Middle Atlantic River Forecasting Center, between 0.25 and 1.5 inches of rain fell in the basin over the past 24 hours. This amounts to a basin-wide average precipitation of about 0.65 inches. Between 0.75 and 1.75 inches of rain is expected over the next 7 days.

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.