March 1, 2009 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 NEAR AVERAGE. THE SNOW PACK ABOVE
TOSTON, MONTANA WAS 89 PERCENT OF AVERAGE. THE SNOW PACK
BETWEEN TOSTON AND FORT PECK, MONTANA WAS 89 PERCENT. THE
SNOW PACK IN THE ST MARY AND MILK RIVER BASINS WAS 74 PERCENT.
FEBRUARY PRECIPITATION WAS BELOW AVERAGE ACROSS THE UPPER
MISSOURI BASIN. BASIN PRECIPITATION SUMMARIES FOR THE MISSOURI BASIN
INCLUDE: MILK ST. MARY, 92 PERCENT; MILK CANADA, 91 PERCENT;
LOWER MILK, 96 PERCENT; ABOVE TOSTON, 49 PERCENT; TOSTON TO
FT. PECK, 75 PERCENT.
February 2009 Upper Missouri Mean Precip Oct-Feb WY2009 Upper Missouri Mean Precip
STREAM FLOW IN THE UPPER MISSOURI BASIN IS FORECAST TO BE NEAR
AVERAGE DURING THE UPCOMING SPRING AND SUMMER. THE ST. MARY RIVER
IS FORECAST TO HAVE 83 PERCENT OF AVERAGE APRIL-SEPTEMBER FLOWS.
RUNOFF IS EXPECTED TO RANGE AROUND 85 PERCENT OF AVERAGE FOR THE
MISSOURI BASIN ABOVE FORT PECK, MONTANA. FORECASTS FOR THE MILK
RIVER BASIN CALL FOR AROUND 73 PERCENT OF AVERAGE SPRING SUMMER RUNOFF.
Upper Missouri March 1, 2009 Spring and Summer Streamflow Forecasts
OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA: LIMA RESERVOIR
HAD 95 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 82 PERCENT OF
AVERAGE WATER, GIBSON RESERVOIR HAD 76 PERCENT OF AVERAGE STORED
WATER, AND FRESNO RESERVOIR HAD 93 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; 102 AND 69 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 48 PERCENT
OF AVERAGE RUNOFF IN FEBRUARY.
Yellowstone Basin
THE HIGH ELEVATION SNOW PACK IN THE YELLOWSTONE BASIN WAS NEAR
AVERAGE ON MARCH 1. THE SNOW PACK IN THE UPPER YELLOWSTONE
BASIN WAS 98 PERCENT OF AVERAGE. THE SNOW PACKS IN THE WIND,
BIGHORN, AND SHOSHONE BASINS WERE 84, 99, AND 89 PERCENT OF
AVERAGE, RESPECTIVELY. THE SNOW PACK IN THE TONGUE AND POWDER
BASINS WERE 107 AND 119 PERCENT OF AVERAGE, RESPECTIVELY.
PRECIPITATION DURING THE MONTH OF FEBRUARY WAS BELOW AVERAGE ACROSS
THE YELLOWSTONE BASIN. THE RANGE WAS FROM 85 PERCENT OF AVERAGE
IN UPPER YELLOWSTONE TO 26 PERCENT IN THE WIND RIVER BASIN. THE
BIGHORN BASIN RECEIVED 51 PERCENT OF AVERAGE PRECIPITATION WHILE
THE LITTLE BIGHORN - UPPER TONGUE RECEIVED 80 PERCENT OF AVERAGE.
THE LOWER YELLOWSTONE WAS AT 75 PERCENT OF AVERAGE AND THE POWDER
RIVER HAD 71 PERCENT OF AVERAGE PRECIPITATION.
STREAM FLOW IN THE YELLOWSTONE BASIN IS FORECAST TO BE AVERAGE
DURING THE UPCOMING SPRING AND SUMMER. RUNOFF AT BILLINGS, MONTANA
IS EXPECTED TO BE 96 PERCENT OF AVERAGE, WITH A PROBABLE RANGE
BETWEEN 69 AND 122 PERCENT OF AVERAGE. STREAM FLOW FOR THE
WIND-BIGHORN BASIN ABOVE ST. XAVIER, MONTANA IS FORECAST TO BE
86 PERCENT OF AVERAGE WITH A PROBABLE RANGE OF 22 TO 130 PERCENT
OF AVERAGE FLOW IN SUB-BASINS. FLOW IN THE TONGUE BASIN IS EXPECTED
TO BE 104 TO 110 PERCENT OF AVERAGE WITH A REASONABLY LIKELY RANGE
OF 135 TO 144 PERCENT OF AVERAGE FLOW. FLOWS IN THE POWDER RIVER
ARE EXPECTED TO BE ABOUT 115 PERCENT OF AVERAGE WITH A REASONABLY
LIKELY RANGE OF 67 TO 163 PERCENT.
Yellowstone March 1, 2009 Spring and Summer Streamflow Forecasts
MONTHEND STORAGE WAS 98 PERCENT OF AVERAGE AT BOYSEN RESERVOIR IN
WYOMING, 107 PERCENT OF AVERAGE AT BUFFALO BILL RESERVOIR IN
WYOMING, AND 108 PERCENT OF AVERAGE AT BIGHORN RESERVOIR ON THE
WYOMING/MONTANA BORDER.
RUNOFF DURING FEBRUARY IN THE YELLOWSTONE RIVER WAS 75 PERCENT OF
THE 1971 TO 2000 AVERAGE AT CORWIN SPRINGS, MONTANA AND 96 PERCENT
OF THAT PERIOD`S AVERAGE AT BILLINGS, MONTANA.
Platte Basin
THE HIGH ELEVATION SNOW PACK IN THE UPPER NORTH PLATTE BASIN WAS
106 PERCENT OF AVERAGE ON MARCH 1. THE SNOW PACK IN THE NORTH
PLATTE BASIN BELOW SEMINOE RESERVOIR WAS 84 PERCENT OF AVERAGE.
THE SNOW PACK IN THE SOUTH PLATTE BASIN WAS 97 PERCENT OF AVERAGE.
FEBRUARY PRECIPITATION ACROSS THE PLATTE BASIN WAS BELOW AVERAGE.
PRECIPITATION IN THE NORTH PLATTE BASIN ABOVE SEMINOE RESERVOIR WAS 95
PERCENT OF AVERAGE. IN THE NORTH PLATTE BASIN BETWEEN SEMINOE
RESERVOIR AND GUERNSY RESERVOIR PRECIPITATION WAS 73 PERCENT OF
AVERAGE. THE NORTH PLATTE BASIN BELOW GUERNSY RESERVOIR HAD 93
PERCENT OF AVERAGE FEBRUARY PRECIPITATION. THE HIGH ELEVATIONS
OF THE SOUTH PLATTE BASIN HAD 42 PERCENT OF AVERAGE PRECIPITATION
WHEREAS THE PLAINS HAD 81 PERCENT OF AVERAGE FEBRUARY PRECIPITATION.
February 2009 Platte Mean Precip Oct-Feb WY2009 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
90 TO 110 PERCENT OF AVERAGE. STREAM FLOWS FOR THE NORTH PLATTE
BELOW SEMINOE RESERVOIR ARE FORECAST TO BE 45 TO 100 PERCENT OF
AVERAGE. STREAMS IN THE SOUTH PLATTE BASIN ABOVE SOUTH PLATTE,
COLORADO CAN EXPECT 75 TO 85 PERCENT OF AVERAGE FLOW. FOR THE
REMAINDER OF THE SOUTH PLATTE BASIN FLOWS ARE EXPECTED TO BE ABOUT
75 TO 95 AVERAGE.
North Platte Streamflow Fcst South Platte Streamflow Fcst
STORED WATER IN SOUTH PLATTE BASIN STORED WATER WAS 101 PERCENT OF
AVERAGE ON MARCH 1. STORED WATER IN THE NORTH PLATTE BASIN WAS
81 PERCENT OF AVERAGE FOR THIS TIME OF THE YEAR.
