Monitoring Reports

The Jennings Randolph water supply release, which started at 8:30 AM today (September 10), is currently visible at the USGS stream gage in Luke, MD. The USGS did a rating curve adjustment that resulted in an increase of 71 MGD (110 cfs) at Point of Rocks from this morning's reading. We are watching for the arrival of the Little Seneca release at Little Falls. Past tests have indicated that the time of travel is approximately 29 hours, which would imply the arrival to be at 1:00 PM.

This afternoon we will be requesting concurrence from the general
managers for a release from Jennings Randolph beginning tomorrow
morning. The 50 MGD test release from Little Seneca Reservoir began at
8:00 AM today (September 9) and will continue through 8:00 AM tomorrow
(September 10). The release was observed by Karin Bencala of ICPRB
staff at a location approximately 1 mile downstream of the reservoir.
Flows were observed to be increasing by 9:15 AM. Black Hill Regional
Staff was setting out signs in the park notifying patrons that the

ICPRB COOP has requested concurrence from the utility general managers
to conduct a 50 MGD time of travel test release from approximately
8:00 a.m. on Thursday, September 9 through 8:00 a.m. on Friday,
September 10.

The weather update remains the same as this morning.

The basin did not receive any precipitation in the past 24 hours. Both the 48-hour and the five-day National Weather Service precipitation forecasts indicate no accumulated
rainfall in the basin, except for trace amounts in the North Branch area.

The basin continues to receive no precipitation, except for the small
amount seen yesterday. Both the 48-hour and the five-day National
Weather Service precipitation forecasts indicate no accumulated
rainfall in the basin. Given current conditions, enhanced monitoring
will likely begin tomorrow. Tomorrow we will contact the utilities
directly to confirm procedures.

Except for scattered amounts of trace rainfall yesterday, the basin has not received any precipitation over the past 7 days. The National
Weather Service predicts no precipitation in the basin over the next 48-hour period. A small amount of rain, up to 1/10 of an inch, is
being forecasted to fall in the North Branch area within the next five days. It appears that the artificially varied flow (AVF) release from
Jennings Randolph has reached Little Falls causing increased flow at the gage. It is expected that flows will drop again once the AVF

Over the last 24 hours, less than a 0.1 of an inch of precipitation fell over the mainstem of the Potomac between Goose Creek and the Monocacy; the remaining areas in the basin received no rain. Over the next 48 hours, the National Weather Service indicates a chance of up to 0.1 of an inch of rain in the North Branch, with a possibility of a 0.25 of an inch in the Washington, D.C. area. Over the next 5 days, there is a chance of up to 0.1 of an inch of rain, with most of the central portion of the basin receiving no rain.

No precipitation fell in the basin yesterday, except for an isolated amount of trace rainfall over the mainstem between Goose Creek and the Monocacy. The trajectory of Hurricane Earl remains off the coast and it does not appear that the basin will receive any precipitation from this event. The National Weather Service does indicate a chance of up to 0.10 of an inch of rain in the next 48 hours in the North Branch area. The flow at Point of Rocks reflects the artificially varied flow release reaching the gage.

Negligible amounts of precipitation have been observed in the Potomac basin over the past couple of days. The National Weather Service (NWS) forecasts show no predicted precipitation over the next 48-hour period. As Hurricane Earl moves up the East Coast, the NWS indicates that the 5-day accumulated precipitation could range from 0.1 and 0.5 inches over most of the basin. The artificially varied flow release is currently passing the Potomac River gage at Hancock, MD.

No precipitation fell in the Potomac basin over the past 24 hours. The National Weather Service predicts little rain over its 5-day forecast period, but the trajectory of Hurricane Earl is uncertain, and it could have an impact on the basin. Last weekend's AVF water quality release from Jennings Randolph Reservoir should be arriving at Little Falls on Friday. Note: yesterday's daily mean flow values are not available for many Potomac basin gages, including Point of Rocks and Little Falls, so values given below for 8/30 are estimated from available real-time data.