National Weather Service United States Department of Commerce

Missouri Basin River Forecast Center
Water Supply Statement
Issued in cooperation with the Natural
Resources Conservation Service
Issued:  September 13, 2011

 

UPPER MISSOURI BASIN
AUGUST PRECIPITATION WAS BELOW AVERAGE ACROSS THE UPPER 
MISSOURI BASIN.  BASIN PRECIPITATION SUMMARIES FOR THE MISSOURI 
BASIN INCLUDE: MILK ST. MARY, 22 PERCENT; MILK CANADA, 27 PERCENT; 
LOWER MILK, 88 PERCENT; ABOVE TOSTON, 55 PERCENT; TOSTON TO 
FT. PECK, 38 PERCENT.

OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA:  LIMA RESERVOIR 
HAD 183 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 157 PERCENT 
OF AVERAGE WATER, GIBSON RESERVOIR HAD 102 PERCENT OF AVERAGE STORED
WATER, AND FRESNO RESERVOIR HAD 91 PERCENT OF AVERAGE STORED WATER.  
THE  MAJOR  HYDROELECTRIC  RESERVOIRS  IN  MONTANA (CANYON  FERRY AND
FORT PECK) HAD MONTHEND STORAGE IN THE AVERAGE TO  BELOW AVERAGE 
RANGE; 106 AND 106 PERCENT OF AVERAGE WATER, RESPECTIVELY.

 
YELLOWSTONE BASIN

PRECIPITATION DURING THE MONTH OF AUGUST WAS ABOUT 62 PERCENT OF
AVERAGE IN THE WIND RIVER BASIN ABOVE BOYSEN RESERVOIR, 74 PERCENT
OF AVERAGE IN THE UPPER YELLOWSTONE BASIN, 62 PERCENT OF AVERAGE
IN THE BIGHORN BASIN, 114 PERCENT OF AVERAGE IN THE LITTLE BIGHORN-
-UPPER TONGUE BASINS, 81 PERCENT OF AVERAGE IN THE POWDER RIVER
BASIN, AND 92 PERCENT OF AVERAGE IN THE LOWER YELLOWSTONE BASIN.

MONTHEND STORAGE WAS 111 PERCENT OF AVERAGE AT BIGHORN RESERVOIR ON
THE WYOMING/MONTANA BORDER.

 

PLATTE BASIN



PRECIPITATION DURING AUGUST IN THE PLATTE BASIN WAS BELOW AVERAGE.
AUGUST PRECIPITATION IN THE NORTH PLATTE BASIN ABOVE SEMINOE
RESERVOIR WAS 68 PERCENT OF AVERAGE. IN THE NORTH PLATTE BASIN
BETWEEN SEMINOE RESERVOIR AND GUERNSY RESERVOIR PRECIPITATION WAS 56
PERCENT OF AVERAGE. THE NORTH PLATTE BASIN BELOW GUERNSY RESERVOIR
HAD 86 PERCENT OF AVERAGE PRECIPITATION. THE HIGH ELEVATIONS OF THE
SOUTH PLATTE BASIN HAD 68 PERCENT OF AVERAGE AUGUST PRECIPITATION
WHEREAS THE PLAINS HAD 67 PERCENT OF AVERAGE PRECIPITATION.

STORED WATER IN THE SOUTH PLATTE BASIN WAS 121 PERCENT OF AVERAGE.

 

 

PRECIPITATION MAPS
August 2011  WY 2011
August 2011 Precipitation Percent of 1971-2000 Average WY2011 Precipitation as Percent of 1971-2000 Average
August 2011 Basin Mean Precipitation          WY2011 Basin Mean Precipitation
August 2011 MBRFC Basin Mean Precipitation      WY2011 MBRFC Basin Mean Precipitation