Over the last 24 hours up to half an inch of rain fell around and upstream of the metro area. The National Weather Service indicates a chance of rain across the entire basin over the next 24 hours. The western areas can expect between trace amounts and half an inch. The predicted totals increase to the east, with up to 1.25 inches expected in the metro area. There is also a chance of a small amount of additional rain on Thursday.
Over the last 24 hours 0.1 to 0.75 inches of rain fell in the central portion of the basin, with the most falling along the border between Fairfax and Prince William counties. The National Weather Service indicates a chance of rain across the basin beginning Wednesday night through Thursday afternoon. Total rainfall amounts are predicted between 0.1 and 1.0 inch. The heaviest rainfall is forecast in the metro area and areas to the east.
Scattered rain, ranging from trace amounts to almost half an inch, occurred in localized portions of the basin over the last 24 hours according to the National Weather Service. The Middle Atlantic River Forecast Center predicts that less than 0.1 inch of rain may fall in a small area of the far western portion of the basin over the next 72 hours. No precipitation is expected across the rest of the basin during that period.
Trace amounts of rain fell in a limited area between the USGS gage at Point of Rocks, MD and Washington, D.C. over the last 24 hours. The National Weather Service indicates there is a chance of 0.03 to 0.10 inches of rain over the next 72 hours and 0 to 0.5 inches over the next 7 days.
Thank you again to those sending in weekend daily withdrawal numbers.
No rain fell in the basin over the last 24 hours. The National Weather Service indicates that there is a chance of trace rainfall over the next 72 hours and 0.1 to 0.5 inches distributed around the basin over the next 7 days.
Thank you to those sending in weekend daily withdrawal numbers. Please continue to send them to coop@icprb.org by 8 am on Sunday.
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.