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:  August 12, 2011

 

 

UPPER MISSOURI BASIN

 

JULY PRECIPITATION WAS ABOVE AVERAGE ACROSS THE UPPER MISSOURI
BASIN.  BASIN PRECIPITATION SUMMARIES FOR THE MISSOURI BASIN INCLUDE:
MILK ST. MARY, 79 PERCENT; MILK CANADA, 65 PERCENT; LOWER MILK, 88
PERCENT; ABOVE TOSTON, 63 PERCENT; TOSTON TO FT. PECK, 70 PERCENT.

OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA:  LIMA RESERVOIR
HAD 193 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 197 PERCENT OF
AVERAGE WATER, GIBSON RESERVOIR HAD 167 PERCENT OF AVERAGE STORED
WATER, AND FRESNO RESERVOIR HAD 131 PERCENT OF AVERAGE STORED WATER.
THE  MAJOR  HYDROELECTRIC  RESERVOIRS  IN  MONTANA (CANYON  FERRY AND
FORT PECK) HAD MONTHEND STORAGE IN THE ABOVE AVERAGE RANGE; 108 AND
121 PERCENT OF AVERAGE WATER, RESPECTIVELY.

AS INDICATED BY THE U.S. GEOLOGICAL LONG TERM GAGING STATIONS,
THE MARIAS RIVER NEAR SHELBY, MONTANA HAD AN ESTIMATED 207 PERCENT
OF AVERAGE RUNOFF IN JULY.

 

YELLOWSTONE BASIN


 

PRECIPITATION DURING THE MONTH OF JULY WAS ABOUT 39 PERCENT OF
AVERAGE IN THE WIND RIVER BASIN ABOVE BOYSEN RESERVOIR, 60 PERCENT
OF AVERAGE IN THE UPPER YELLOWSTONE BASIN, 27 PERCENT OF AVERAGE
IN THE BIGHORN BASIN, AND 79 PERCENT OF AVERAGE IN THE LITTLE
BIGHORN BASINS-UPPER TONGUE BASINS, 54 PERCENT OF AVERAGE IN THE
POWDER RIVER BASIN, AND 107 PERCENT OF AVERAGE IN THE LOWER
YELLOWSTONE BASIN.

MONTHEND STORAGE WAS 129 PERCENT OF AVERAGE AT BIGHORN RESERVOIR ON
THE WYOMING/MONTANA BORDER. MONTHEND STORAGE WAS NOT REPORTED AT
BOYSEN RESERVOIR OR AT BUFFALO BILL RESERVOIR IN WYOMING.

RUNOFF DURING JULY 2011 IN THE YELLOWSTONE RIVER WAS 241 PERCENT OF
AVERAGE AT CORWIN SPRINGS AND 273 PERCENT OF NORMAL AT BILLINGS,
MONTANA. (HTTP:/MT.WATER.USGS.GOV/PUB/NWC.RELEASE.HTML)

 

 

PLATTE BASIN


 

PRECIPITATION DURING JULY IN THE PLATTE BASIN WAS BELOW
AVERAGE. JULY PRECIPITATION IN THE NORTH PLATTE BASIN
ABOVE SEMINOE RESERVOIR WAS 152 PERCENT OF AVERAGE. IN THE
NORTH PLATTE BASIN BETWEEN SEMINOE RESERVOIR AND GUERNSY
RESERVOIR PRECIPITATION WAS 72 PERCENT OF AVERAGE. THE NORTH
PLATTE BASIN BELOW GUERNSY RESERVOIR HAD 88 PERCENT OF AVERAGE
PRECIPITATION. THE HIGH ELEVATIONS OF THE SOUTH PLATTE BASIN HAD
155 PERCENT OF AVERAGE JULY PRECIPITATION WHEREAS THE PLAINS
HAD 137 PERCENT OF AVERAGE PRECIPITATION.

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

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