March 1, 2008 Spring and Summer Streamflow Forecasts
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 107 PERCENT OF AVERAGE. THE SNOW PACK
BETWEEN TOSTON AND FORT PECK, MONTANA WAS 101 PERCENT. THE
SNOW PACK IN THE ST MARY AND MILK RIVER BASINS WAS 105 PERCENT.
THE HIGH ELEVATION SNOW PACK IN THE UPPER MISSOURI BASIN AS OF
FEBRUARY 1 WAS NEAR AVERAGE. THE SNOW PACK ABOVE
TOSTON, MONTANA WAS 109 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 94 PERCENT.
FEBRUARY PRECIPITATION WAS ABOVE AVERAGE ACROSS THE UPPER MISSOURI
BASIN. BASIN PRECIPITATION SUMMARIES FOR THE MISSOURI BASIN INCLUDE:
MILK ST. MARY, 107 PERCENT; MILK CANADA, 124 PERCENT; LOWER MILK,
113 PERCENT; ABOVE TOSTON, 120 PERCENT; TOSTON TO FT. PECK, 104 PERCENT.
February 2008 Upper Missouri Mean Precip Oct-Feb WY2008 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 103 PERCENT OF AVERAGE
APRIL-SEPTEMBER FLOWS. RUNOFF IS EXPECTED TO RANGE AROUND 110
PERCENT OF AVERAGE FOR THE MISSOURI BASIN ABOVE FORT PECK, MONTANA.
FORECASTS FOR THE MILK RIVER BASIN CALL FOR AROUND 90 TO 95 PERCENT OF
AVERAGE SPRING SUMMER RUNOFF.
Upper Missouri March 1, 2008 Spring and Summer Streamflow Forecasts
OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA: LIMA RESERVOIR HAD 125 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 74 PERCENT OF AVERAGE WATER, GIBSON RESERVOIR HAD 47 PERCENT OF AVERAGE STORED WATER, AND FRESNO RESERVOIR HAD 55 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; 93 AND 58 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 46 PERCENT
OF AVERAGE RUNOFF IN FEBRUARY.
Yellowstone Basin
THE HIGH ELEVATION SNOW PACK IN THE YELLOWSTONE BASIN WAS MOSTLY
AVERAGE ON MARCH 1. THE SNOW PACK IN THE UPPER YELLOWSTONE BASIN
WAS 103 PERCENT OF AVERAGE. THE SNOW PACKS IN THE WIND, BIGHORN,
AND SHOSHONE BASINS WERE 93, 97, AND 93 PERCENT OF AVERAGE,
RESPECTIVELY. THE SNOW PACKS IN THE TONGUE AND POWDER BASINS WERE
97 AND 110 PERCENT OF AVERAGE, RESPECTIVELY.
PRECIPITATION WAS AVERAGE TO BELOW AVERAGE IN THE YELLOWSTONE BASIN
DURING THE MONTH OF FEBRUARY. PRECIPITATION WAS ABOUT 92 PERCENT
OF AVERAGE IN THE WIND RIVER BASIN ABOVE BOYSEN RESERVOIR, BUT ONLY
46 PERCENT OF AVERAGE IN THE BIGHORN BASIN, AND 68 PERCENT OF
AVERAGE IN THE LITTLE BIGHORN BASIN. THE POWDER RIVER BASIN
RECEIVED 93 PERCENT OF AVERAGE FEBRUARY PRECIPITATION. FEBRUARY
PRECIPITATION WAS 73 PERCENT OF AVERAGE IN THE UPPER YELLOWSTONE
BASIN (ABOVE BILLINGS) AND 91 PERCENT OF AVERAGE IN THE LOWER
YELLOWSTONE BASIN. THE WIND, BIGHORN, AND UPPER YELLOWSTONE BASINS
HAVE RECEIVED ABOVE AVERAGE PRECIPITATION FOR THE WATER YEAR TO
DATE. CUMULATIVE WATER-YEAR VALUES INCLUDE 118 PERCENT, 136 PERCENT,
AND 116 PERCENT OF AVERAGE FOR THESE BASINS, RESPECTIVELY.
STREAM FLOW IN THE YELLOWSTONE BASIN IS FORECAST TO BE MOSTLY ABOUT AVERAGE DURING THE UPCOMING SPRING AND SUMMER. RUNOFF AT BILLINGS, MONTANA IS EXPECTED TO BE 107 PERCENT OF AVERAGE, WITH A PROBABLE RANGE BETWEEN 81 AND 133 PERCENT OF AVERAGE. STREAM FLOW FOR THE WIND-BIGHORN BASIN ABOVE ST. XAVIER, MONTANA IS FORECAST TO BE 91 PERCENT OF AVERAGE WITH A PROBABLE RANGE OF 26 TO 129 PERCENT OF AVERAGE FLOW IN SUB-BASINS. FLOW IN THE TONGUE BASIN IS EXPECTED TO BE 96 PERCENT OF AVERAGE WITH A REASONABLY LIKELY RANGE OF 58 TO 134 PERCENT OF AVERAGE FLOW. FLOWS IN THE POWDER RIVER ARE EXPECTED TO BE ABOUT 92 PERCENT OF AVERAGE WITH A REASONABLY LIKELY RANGE OF 66 TO 119 PERCENT.
Yellowstone March 1, 2008 Spring and Summer Streamflow Forecasts
END-OF-FEBRUARY RESERVOIR STORAGE IN WYOMING WAS 68 PERCENT OF
AVERAGE IN BOYSEN RESERVOIR AND 111 PERCENT OF AVERAGE IN BUFFALO
BILL RESERVOIR. MONTHEND STORAGE WAS 101 PERCENT OF AVERAGE IN
BIGHORN RESERVOIR ON THE WYOMING/MONTANA BORDER.
RUNOFF DURING FEBRUARY IN THE YELLOWSTONE RIVER WAS ESTIMATED TO BE
62 PERCENT OF THE 1971 TO 2000 AVERAGE AT CORWIN SPRINGS AND 79
PERCENT OF THAT PERIOD`S AVERAGE AT BILLINGS.
Platte Basin
THE HIGH ELEVATION SNOW PACK IN THE UPPER NORTH PLATTE BASIN WAS
107 PERCENT OF AVERAGE ON FEBRUARY 1. THE SNOW PACK IN THE NORTH
PLATTE BASIN BELOW SEMINOE RESERVOIR WAS 92 PERCENT OF AVERAGE.
THE SNOW PACK IN THE SOUTH PLATTE BASIN WAS 109 PERCENT OF AVERAGE.
PRECIPITATION DURING FEBRUARY IN THE PLATTE BASIN RANGED FROM BELOW
AVERAGE TO ABOVE AVERAGE. FEBRUARY PRECIPITATION IN THE NORTH
PLATTE BASIN ABOVE SEMINOE RESERVOIR WAS 140 PERCENT OF AVERAGE.
IN THE NORTH PLATTE BASIN BETWEEN SEMINOE RESERVOIR AND GUERNSY
RESERVOIR PRECIPITATION WAS 98 PERCENT OF AVERAGE. THE NORTH
PLATTE BASIN BELOW GUERNSY RESERVOIR HAD 89 PERCENT OF AVERAGE
PRECIPITATION. THE HIGH ELEVATIONS OF THE SOUTH PLATTE BASIN HAD
135 PERCENT OF AVERAGE FEBRUARY PRECIPITATION WHEREAS THE PLAINS
HAD 78 PERCENT OF AVERAGE PRECIPITATION.
February 2008 Platte Mean Precip Oct-Feb WY2008 Platte Mean Precip
STREAM FLOW IN THE PLATTE BASIN IS FORECAST TO RANGE FROM BELOW
AVERAGE TO ABOVE AVERAGE DURING THE UPCOMING SPRING AND SUMMER.
RUNOFF FOR STREAMS ABOVE SEMINOE RESERVOIR ARE EXPECTED TO BE ABOUT
100 TO 120 PERCENT OF AVERAGE. STREAM FLOWS FOR THE NORTH PLATTE
BELOW SEMINOE RESERVOIR ARE FORECAST TO BE 65 TO 120 PERCENT OF
AVERAGE. THE SOUTH PLATTE BASIN ABOVE SOUTH PLATTE, COLORADO CAN
EXPECT ABOUT 110 TO 115 PERCENT OF AVERAGE FLOW. FOR THE REMAINDER
OF THE SOUTH PLATTE BASIN FLOWS ARE EXPECTED TO BE ABOUT 95 TO
115 AVERAGE.
North Platte Streamflow Fcst South Platte Streamflow Fcst
STORED WATER IN THE NORTH PLATTE BASIN AS OF MARCH 1 WAS 45 PERCENT
OF AVERAGE. IN THE SOUTH PLATTE BASIN STORED WATER WAS 90 PERCENT OF
AVERAGE.
