Monitoring Reports

Adams County, PA, and nearby areas saw some rain yesterday. According to the Middle Atlantic River Forecast Center, accumulations of up to 1/10 inches are expected in the far northern portion of the Potomac basin over the next 3 days, primarily in Pennsylvania. The 7-day forecast is not as promising as it was a few days ago, but accumulations of 1/4 to 3/4 inches are expected throughout most of the basin, mostly occurring Sunday through Tuesday.

Trace amounts of rain fell over some northern areas of the basin over the past 24 hours according to the Middle Atlantic River Forecast Center. Forecasts are calling for 0.5 to 1.5 inches of rainfall across much of the basin over the next 7 days.

REVISION 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)

According to Middle Atlantic River Forecast Center estimates, no rain fell in the basin in the past 24 hours. However, streamflows have risen slightly due to Monday's rain, and forecasts call for over an inch and a half of rain throughout most of the basin over the next 7 days.

REVISION 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 unexpected showers brought some needed relief to the basin, and streamflows are increasing slightly. According to Middle Atlantic River Forecast Center estimates, most of the basin received between 0.25 to 0.75 inches of rain over the past 24 hours. However, no rain is expected over the next 3 days.

There was no rain in most of the Potomac basin over the past 24 hours, but according to Middle Atlantic River Forecast Center (MARFC) estimates, 0.25 to 0.50 inches of rain fell in a few isolated locations in the western part of the basin yesterday. Forecasts call for the dry conditions to continue, but the MARFC predicts precipitation accumulations of over 0.10 inches in the far western portion of the basin over the next 3 days.

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

According to the Middle Atlantic River Forecast Center, little precipitation fell in the basin over the past 24 hours, and little is expected for the next three days.

According to Middle Atlantic River Forecast Center estimates, little or no rain fell in the Potomac basin over the past 24 hours. According to forecasts, 0.01 to 0.75 inches of rain is expected for the next 7 days (very little of this rain is expected for the next 5 days).

According to Middle Atlantic River Forecast Center estimates, little or no rain fell in the Potomac basin over the past 72 hours. According to forecasts, no significant rain is expected for the next 7 days.

Yesterday brought no relief from the dry conditions in the Potomac basin. The National Weather Service forecasts negligible accumulations of precipitation over the next 7 days.

Daily Flows:
Little Falls gage flow 2019-09-25: 1060 MGD (1640 cfs)
Little Falls gage flow 2019-09-26: 1034 MGD (est., based on recently available real time data) (1600 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.

Dry conditions persist, with negligible precipitation in the Potomac basin over the past several days. The National Weather Service's forecast calls for little rain over the next 7 days.

Daily Flows:
Little Falls gage flow 2019-09-24: 1053 MGD (1630 cfs)
Little Falls gage flow 2019-09-25: 1034 MGD (est., based on recently available real time data) (1600 cfs)
Note: Gage flow at Little Falls is measured after water supply withdrawals.