April 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 APRIL 1 WAS NEAR AVERAGE. THE SNOW PACK ABOVE TOSTON, MONTANA WAS 103 PERCENT OF AVERAGE. THE SNOW PACK BETWEEN TOSTON AND FORT PECK, MONTANA WAS 104 PERCENT. THE SNOW PACK IN THE ST MARY AND MILK RIVER BASINS WAS 84 PERCENT. MARCH PRECIPITATION WAS ABOVE AVERAGE ACROSS THE UPPER MISSOURI BASIN. BASIN PRECIPITATION SUMMARIES FOR THE MISSOURI BASIN INCLUDE: MILK ST. MARY, 120 PERCENT; MILK CANADA, 53 PERCENT; LOWER MILK, 41 PERCENT; ABOVE TOSTON, 187 PERCENT; TOSTON TO FT. PECK, 104 PERCENT.
March 2009 Upper Missouri Mean Precip Oct-Mar 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 90 PERCENT OF AVERAGE APRIL-SEPTEMBER FLOWS.
RUNOFF IS EXPECTED TO RANGE AROUND 104 PERCENT OF AVERAGE FOR THE
MISSOURI BASIN ABOVE FORT PECK, MONTANA. FORECASTS FOR THE MILK
RIVER BASIN CALL FOR AROUND 90 PERCENT OF AVERAGE SPRING SUMMER RUNOFF.
Upper Missouri April 1, 2009 Spring and Summer Streamflow Forecasts
OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA: LIMA RESERVOIR
HAD 96 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 84 PERCENT OF
AVERAGE WATER, GIBSON RESERVOIR HAD 74 PERCENT OF AVERAGE STORED
WATER, AND FRESNO RESERVOIR HAD 78 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; 103 AND 72 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 126 PERCENT
OF AVERAGE RUNOFF IN MARCH.
Yellowstone Basin
THE HIGH ELEVATION SNOW PACK IN THE YELLOWSTONE BASIN WAS NEAR
AVERAGE ON APRIL 1. THE SNOW PACK IN THE UPPER YELLOWSTONE
BASIN WAS 107 PERCENT OF AVERAGE. THE SNOW PACKS IN THE WIND,
BIGHORN, AND SHOSHONE BASINS WERE 93, 103, AND 98 PERCENT OF
AVERAGE, RESPECTIVELY. THE SNOW PACK IN THE TONGUE AND POWDER
BASINS WERE 107 AND 118 PERCENT OF AVERAGE, RESPECTIVELY.
PRECIPITATION DURING THE MONTH OF MARCH WAS ABOVE AVERAGE ACROSS
THE YELLOWSTONE BASIN. PRECIPITATION IN THE UPPER YELLOWSTONE
BASIN WAS 151 PERCENTOF AVERAGE THE WIND RIVER BASIN REPORTED 170
PERCENT OF AVERAGE MARCH PRECIPITATION. THE BIGHORN BASIN RECEIVED
113 PERCENT OF AVERAGE PRECIPITATION WHILE THE LITTLE BIGHORN -
UPPER TONGUE BASIN RECEIVED 102 PERCENT OF AVERAGE. THE LOWER
YELLOWSTONE BASIN RECIVED 107 PERCENT OF AVERAGE AND THE POWDER
RIVER BASIN HAD 184 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 103 PERCENT OF AVERAGE, WITH A PROBABLE RANGE
BETWEEN 77 AND 129 PERCENT OF AVERAGE. STREAM FLOW FOR THE
WIND-BIGHORN BASIN ABOVE ST. XAVIER, MONTANA IS FORECAST TO BE
98 PERCENT OF AVERAGE WITH A PROBABLE RANGE OF 40 TO 130 PERCENT
OF AVERAGE FLOW IN SUB-BASINS. FLOW IN THE TONGUE BASIN IS EXPECTED
TO BE 104 PERCENT OF AVERAGE WITH A REASONABLY LIKELY RANGE
OF 76 TO 146 PERCENT OF AVERAGE FLOW. FLOWS IN THE POWDER RIVER
ARE EXPECTED TO BE ABOUT 110 PERCENT OF AVERAGE WITH A REASONABLY
LIKELY RANGE OF 53 TO 165 PERCENT.
Yellowstone April 1, 2009 Spring and Summer Streamflow Forecasts
MONTHEND STORAGE WAS 100 PERCENT OF AVERAGE AT BOYSEN RESERVOIR IN
WYOMING, 111 PERCENT OF AVERAGE AT BUFFALO BILL RESERVOIR IN
WYOMING, AND 113 PERCENT OF AVERAGE AT BIGHORN RESERVOIR ON THE
WYOMING/MONTANA BORDER.
RUNOFF DURING MARCH IN THE YELLOWSTONE RIVER WAS 80 PERCENT OF THE 1971 TO 2000 AVERAGE AT CORWIN SPRINGS, MONTANA AND 87 PERCENT OF THAT PERIOD`S AVERAGE AT BILLINGS, MONTANA.
Platte Basin
THE HIGH ELEVATION SNOW PACK IN THE UPPER NORTH PLATTE BASIN WAS
104 PERCENT OF AVERAGE ON APRIL 1. THE SNOW PACK IN THE NORTH
PLATTE BASIN BELOW SEMINOE RESERVOIR WAS 88 PERCENT OF AVERAGE.
THE SNOW PACK IN THE SOUTH PLATTE BASIN WAS 91 PERCENT OF AVERAGE.
MARCH PRECIPITATION ACROSS THE PLATTE BASIN RANGED FROM ABOVE
AVERAGE TO BELOW AVERAGE. PRECIPITATION IN THE NORTH PLATTE BASIN
ABOVE SEMINOE RESERVOIR WAS 118 PERCENT OF AVERAGE. IN THE NORTH
PLATTE BASIN BETWEEN SEMINOE RESERVOIR AND GUERNSY RESERVOIR
PRECIPITATION WAS 129 PERCENT OF AVERAGE. THE NORTH PLATTE BASIN
BELOW GUERNSY RESERVOIR HAD 107 PERCENT OF AVERAGE MARCH
PRECIPITATION. THE HIGH ELEVATIONS OF THE SOUTH PLATTE BASIN HAD
71 PERCENT OF AVERAGE PRECIPITATION WHEREAS THE PLAINS HAD 63 PERCENT
OF AVERAGE PRECIPITATION.
March 2009 Platte Mean Precip Oct-Mar 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 105 PERCENT OF AVERAGE. STREAM FLOWS FOR THE NORTH PLATTE BELOW SEMINOE RESERVOIR ARE FORECAST TO BE 50 TO 90 PERCENT OF AVERAGE. STREAMS IN THE SOUTH PLATTE BASIN ABOVE SOUTH PLATTE, COLORADO CAN EXPECT 75 TO 80 PERCENT OF AVERAGE FLOW. FOR THE REMAINDER OF THE SOUTH PLATTE BASIN FLOWS ARE EXPECTED TO BE ABOUT 45 TO 85 AVERAGE.
North Platte Streamflow Fcst South Platte Streamflow Fcst
STORED WATER IN SOUTH PLATTE BASIN STORED WATER WAS 94 PERCENT OF
AVERAGE ON APRIL 1. STORED WATER IN THE NORTH PLATTE BASIN WAS
84 PERCENT OF AVERAGE FOR THIS TIME OF THE YEAR.
