A negligible amount of rain fell in limited areas over the last 24 hours. The National Weather Service indicates there is a chance of trace rainfall over the next 72 hours and up to 0.1 inches total over the next 7 days across much of the basin.
We will continue daily monitoring over the weekend. If you are responsible for sending us daily withdrawals, please send them to coop@icprb.org by 8am on both Saturday and Sunday. Thank you!
Flow at Point of Rocks is currently 1780 cfs, which is below CO-OP's low-flow monitoring threshold of 2,000 cfs. The rating curve at Point of Rocks was changed on Tuesday by the USGS to more accurately reflect channel conditions, and reported flows over the past several weeks were adjusted downward.
Point of Rocks flow is at 4,820 cfs. Within the last 24 hours the Potomac basin has received between 0.1 and 5 inches of precipitation. Rain is expected to continue over the next 72 hours bringing new precipitation amounts between 0.25 and 2 inches.
With rain continuing to fall across much of the basin, and Point of Rocks flow being above the low flow monitoring threshold of 2,000 cfs, daily monitoring will be discontinued until further notice. Thank you to all for your contribution to the monitoring efforts.
With rain continuing to fall across much of the basin, flow at the Point of Rocks gage is 1,910 cfs. Over the past 24 hours, rainfall in the basin has ranged from zero in the west to 1.5 inches in the southeast. The 72-hour forecast predicts between 0.5 and 2 inches of rain across the basin, increasing from west to east.
Flows in basin streams have risen modestly due to Monday's rain event, but flow at Point of Rocks remains below 2000 cfs. National Weather Service forecasts call for more rain over the next 72 hours, though the highest accumulations are expected to be in the eastern portion of the basin.
While the entire basin received significant rainfall yesterday, flow at the Point of Rocks gage has not yet risen much. MARFC predicts that flow will rise above 2,000 cfs sometime tomorrow. The highest rainfall amounts, between 1.25 and 1.75 inches, fell in the central part of the basin. The other areas received between 0.25 and 1.25 inches. The 72-hour forecast shows a chance of 0.25 and 1.50 inches of rain, with the amounts increasing in bands from west to east.
Flow at the Point of Rocks gage dropped approximately 400 cfs over the weekend. The western portion of the basin received between trace amounts and 0.5 inches of rain over the last 24 hours. The 72-hour forecast shows a chance of 0.5 to 1.25 inches of rain across the basin. The NOAA/MARFC briefing from Sunday, October 6, indicates that this rain is from a cold front crossing the region, not from Tropical Depression Karen. The heaviest rain is expected east of the I-95 corridor.
Potomac River flows at Point of Rocks and Little Falls are still slightly higher due to last weekend's water quality releases from the North Branch reservoirs. The basin is expected to receive some precipitation - trace amounts up to a half inch - on Sunday. The Middle Atlantic River Forecast Center predicts that flow at Point of Rocks will fall to 1720 cfs over the next 72 hours.
Because flow conditions are expected to be relatively stable over the next 72 hours, CO-OP's daily drought monitoring and reporting will be suspended over the weekend, and will resume on Monday.
No rain fell in the basin over the last 24 hours and none is predicted for the next 72-hour period. The rise in flow at Point of Rocks is due to the release this weekend from the North Branch Reservoirs.
According to the National Weather Service, there was 0 to 0.25 inches of rain in the basin over the last 24 hours. A tenth of an inch of rain in the North Branch is predicted for the next 72 hours.