Missouri River Basin Streamflow Forecast Missouri River Basin Mountain Snowpack
Upper Missouri Basin
THE HIGH ELEVATION SNOW PACK IN THE UPPER MISSOURI BASIN AS OF
MARCH 1 WAS SLIGHTLY BELOW AVERAGE. THE SNOW PACK ABOVE
TOSTON, MONTANA WAS 83 PERCENT OF AVERAGE. THE SNOW PACK
BETWEEN TOSTON AND FORT PECK, MONTANA WAS 92 PERCENT. THE
SNOW PACK IN THE ST MARY AND MILK RIVER BASINS WAS 89 PERCENT.
FEBRUARY PRECIPITATION WAS ABOVE AVERAGE ACROSS THE UPPER MISSOURI
BASIN. BASIN PRECIPITATION SUMMARIES FOR THE MISSOURI BASIN INCLUDE:
MILK ST. MARY, 116 PERCENT; MILK CANADA, 304 PERCENT; LOWER MILK,
182 PERCENT; ABOVE TOSTON, 185 PERCENT; TOSTON TO FT. PECK, 240 PERCENT.
February 2007 Upper Missouri Mean Precip Oct-Feb WY2007 Upper Missouri Mean Precip
STREAM FLOW IN THE UPPER MISSOURI BASIN IS FORECAST TO BE AVERAGE
TO SLIGHTLY BELOW AVERAGE DURING THE UPCOMING SPRING AND SUMMER.
THE ST. MARY RIVER IS FORECAST TO HAVE 98 PERCENT OF AVERAGE
APRIL-SEPTEMBER FLOWS. RUNOFF IS EXPECTED TO RANGE AROUND 78
PERCENT OF AVERAGE FOR THE MISSOURI BASIN ABOVE FORT PECK, MONTANA.
FORECASTS FOR THE MILK RIVER BASIN CALL FOR AROUND 100 PERCENT OF
AVERAGE SPRING SUMMER RUNOFF.
OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA: LIMA RESERVOIR
HAD 125 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 80 PERCENT OF
AVERAGE WATER, GIBSON RESERVOIR HAD 96 PERCENT OF AVERAGE STORED
WATER, AND FRESNO RESERVOIR HAD 77 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; 100 AND 56 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 68 PERCENT
OF AVERAGE RUNOFF IN FEBRUARY.
Yellowstone Basin
THE HIGH ELEVATION SNOW PACK IN THE YELLOWSTONE BASIN WAS MOSTLY
BELOW AVERAGE ON MARCH 1. THE SNOW PACK IN THE UPPER
YELLOWSTONE BASIN WAS 81 PERCENT OF AVERAGE. THE SNOW PACKS IN
THE WIND, BIGHORN, AND SHOSHONE BASINS WERE 75, 81, AND 72 PERCENT
OF AVERAGE, RESPECTIVELY. THE SNOW PACKS IN THE TONGUE AND POWDER
BASINS WERE 93 AND 83 PERCENT OF AVERAGE, RESPECTIVELY.
PRECIPITATION WAS WELL ABOVE AVERAGE THROUGHOUT THE YELLOWSTONE
BASIN DURING THE MONTH OF FEBRUARY. PRECIPITATION WAS ABOUT 51
PERCENT OF AVERAGE IN THE WIND RIVER BASIN ABOVE BOYSEN RESERVOIR,
161 PERCENT OF AVERAGE IN THE BIGHORN BASIN, AND 134 PERCENT OF
AVERAGE IN THE LITTLE BIGHORN BASIN. THE POWDER RIVER BASIN
RECEIVED 167 PERCENT OF AVERAGE FEBRUARY PRECIPITATION.
FEBRUARY PRECIPITATION WAS 137 PERCENT OF AVERAGE IN THE UPPER
YELLOWSTONE BASIN (ABOVE BILLINGS) AND 206 PERCENT OF AVERAGE IN
THE LOWER YELLOWSTONE BASIN. FOR THE WATER YEAR TO DATE, ONLY THE
UPPER YELLOWSTONE BASIN AND BIGHORN BASIN HAVE RECEIVED ABOVE
AVERAGE PRECIPITATION, WITH 121 PERCENT AND 109 PERCENT OF
AVERAGE SEASONAL PRECIPITATION, RESPECTIVELY.
STREAM FLOW IN THE YELLOWSTONE BASIN IS FORECAST TO BE MOSTLY BELOW
AVERAGE DURING THE UPCOMING SPRING AND SUMMER. RUNOFF AT
BILLINGS, MONTANA IS EXPECTED TO BE 88 PERCENT OF AVERAGE, WITH
A PROBABLE RANGE BETWEEN 62 AND 114 PERCENT OF AVERAGE. STREAM
FLOW FOR THE WIND-BIGHORN BASIN ABOVE ST. XAVIER, MONTANA IS
FORECAST TO BE 68 PERCENT OF AVERAGE WITH A PROBABLE RANGE
OF 41 TO 94 PERCENT OF AVERAGE FLOW IN SUB-BASINS. FLOW IN THE
TONGUE BASIN IS EXPECTED TO BE 80 TO 90 PERCENT OF AVERAGE WITH
A REASONABLY LIKELY RANGE OF 40 TO 120 PERCENT OF AVERAGE FLOW.
FLOWS IN THE POWDER RIVER ARE EXPECTED TO BE ABOUT 62 PERCENT OF
AVERAGE WITH A REASONABLY LIKELY RANGE OF 35 TO 107 PERCENT.
MONTHEND STORAGE WAS NOT REPORTED AT EITHER BOYSEN RESERVOIR OR
BUFFALO BILL RESERVOIR IN WYOMING. MONTHEND STORAGE WAS
93 PERCENT OF AVERAGE AT BIGHORN RESERVOIR ON THE WYOMING/MONTANA
BORDER.
RUNOFF DURING FEBRUARY IN THE YELLOWSTONE RIVER WAS 92 PERCENT
OF THE 1971 TO 2000 AVERAGE AT CORWIN SPRINGS AND 91 PERCENT
OF THAT AVERAGE AT BILLINGS.
Platte Basin
THE HIGH ELEVATION SNOW PACK IN THE UPPER NORTH PLATTE BASIN WAS
85 PERCENT OF AVERAGE. THE SNOW PACK IN THE NORTH PLATTE BASIN
BELOW SEMINOE RESERVOIR WAS 87 PERCENT OF AVERAGE. THE SNOW PACK
IN THE SOUTH PLATTE BASIN WAS 113 PERCENT.
PRECIPITATION ACROSS THE PLATTE BASIN WAS ABOVE AVERAGE TO ABOVE
AVERAGE FOR THE MONTH OF JANUARY PRECIPITATION IN NORTH PLATTE BASIN
ABOVE SEMINOE RESERVOIR WAS 82 PERCENT AVERAGE. IN THE NORTH
PLATTE BASIN BETWEEN SEMINOE RESERVOIR AND GUERNSY RESERVOIR
PRECIPITATION WAS 62 PERCENT OF AVERAGE. THE NORTH PLATTE BASIN BELOW
GUERNSY RESERVOIR HAD 68 PERCENT OF AVERAGE PRECIPITATION. THE HIGH
ELEVATIONS OF THE SOUTH PLATTE BASIN HAD 82 PERCENT OF AVERAGE
PRECIPITATION WHEREAS THE PLAINS HAD 76 PERCENT OF AVERAGE
PRECIPITATION.
February 2007 Platte Mean Precip Oct-Feb WY2007 Platte Mean Precip
STREAM FLOW IN THE PLATTE BASIN IS FORECAST TO RANGE FROM BELOW AVERAGE
TO AVERAGE DURING THE UPCOMING SPRING AND SUMMER. RUNOFF FOR STREAMS
ABOVE SEMINOE RESERVOIR ARE EXPECTED TO BE ABOUT 85 TO 90 PERCENT OF
AVERAGE. STREAM FLOW FOR THE NORTH PLATTE BELOW SEMINOE RESERVOIR ARE
FORECAST TO BE BETWEEN 60 TO 80 PERCENT OF AVERAGE. HOWEVER THE LARAMIE
RIVER IS FORECAST TO HAVE AVERAGE RUNOFF. THE SOUTH PLATTE BASIN ABOVE
SOUTH PLATTE, COLORADO CAN EXPECT ABOUT BETWEEN 100 AND 110 PERCENT OF
AVERAGE FLOW. FOR THE REMAINDER OF THE SOUTH SLATTE BASIN FLOWS
ARE EXPECTED TO BE ABOUT 100 PERCENT OF AVERAGE.
STORED WATER IN THE NORTH PLATTE BASIN AS OF MARCH 1 WAS 86
PERCENT OF AVERAGE.
