June 1, 2007 Spring and Summer Streamflow Forecasts
Upper Missouri Basin
MAY PRECIPITATION WAS ABOVE AVERAGE ACROSS MOST OF THE UPPER MISSOURI
BASIN. ABOVE TOSTON, MILK ST. MARY AND CANADA WERE NEAR AVERAGE. BASIN
PRECIPITATION SUMMARIES FOR THE MISSOURI BASIN INCLUDE: MILK ST. MARY,
94 PERCENT; MILK CANADA, 91 PERCENT; LOWER MILK, 223 PERCENT; ABOVE TOSTON,
96 PERCENT; TOSTON TO FT. PECK, 166 PERCENT.
May 2007 Upper Missouri Mean Precip Oct-May WY2007 Upper Missouri Mean Precip
STREAM FLOW IN THE UPPER MISSOURI BASIN IS FORECAST TO BE BELOW AVERAGE
DURING THE UPCOMING SPRING AND SUMMER. THE ST. MARY RIVER IS FORECAST TO
HAVE 91 PERCENT OF AVERAGE JUNE-SEPTEMBER FLOWS. RUNOFF IS EXPECTED TO
RANGE AROUND 45 PERCENT OF AVERAGE FOR THE MISSOURI BASIN ABOVE FORT
PECK, MONTANA. FORECASTS FOR THE MILK RIVER BASIN CALL FOR AROUND 70
PERCENT OF AVERAGE SPRING SUMMER RUNOFF.
Upper Missouri June 1, 2007 Spring and Summer Streamflow Forecasts
OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA: LIMA RESERVOIR
HAD 106 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 72 PERCENT OF
AVERAGE WATER, GIBSON RESERVOIR HAD 108 PERCENT OF AVERAGE STORED
WATER, AND FRESNO RESERVOIR HAD 112 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; 107 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 62 PERCENT.
Yellowstone Basin
PRECIPITATION DURING THE MONTH OF MAY WAS ABOUT 72 PERCENT OF
AVERAGE IN THE WIND RIVER BASIN ABOVE BOYSEN RESERVOIR, 79 PERCENT
OF AVERAGE IN THE UPPER YELLOWSTONE BASIN, 70 AND 194 PERCENT OF
AVERAGE IN THE BIGHORN AND LITTLE BIGHORN BASINS, RESPECTIVELY,
199 PERCENT OF AVERAGE IN THE POWDER-TONGUE BASINS, AND 232 PERCENT
OF AVERAGE IN THE LOWER YELLOWSTONE BASIN.
STREAM FLOW IN MOST OF THE YELLOWSTONE BASIN IS FORECAST TO BE WELL
BELOW AVERAGE DURING THE UPCOMING SPRING AND SUMMER. RUNOFF AT
BILLINGS, MONTANA IS EXPECTED TO BE NEAR 52 PERCENT OF AVERAGE.
STREAM FLOW FOR THE WIND-BIGHORN BASIN ABOVE ST. XAVIER, MONTANA IS
FORECAST TO BE ABOUT 45 PERCENT OF AVERAGE.
Yellowstone June 1, 2007 Spring and Summer Streamflow Forecasts
FLOW IN THE TONGUE BASIN IS NOT FORECAST IN JUNE BECAUSE THE
STATISTICAL METHODOLOGY USED HAS A PRIMARY DEPENDENCY ON SNOWPACK,
WHILE FROM JUNE THROUGH SEPTEMBER TONGUE RIVER RUNOFF IS MORE
CLOSELY RELATED TO RAINFALL.
MONTHEND STORAGE WAS AT 78 PERCENT OF AVERAGE AT BOYSEN RESERVOIR
IN WYOMING, 142 PERCENT OF AVERAGE AT BUFFALO BILL RESERVOIR IN
WYOMING, AND 105 PERCENT OF AVERAGE AT BIGHORN RESERVOIR ON THE
WYOMING/MONTANA BORDER.
RUNOFF DURING MAY IN THE YELLOWSTONE RIVER WAS 114 PERCENT
OF THE 1971 TO 2000 AVERAGE AT CORWIN SPRINGS, MONTANA AND 109
PERCENT OF THAT AVERAGE AT BILLINGS, MONTANA.
Platte Basin
PRECIPITATION ACROSS THE PLATTE BASIN WAS BELOW AVERAGE TO BELOW
AVERAGE FOR THE MONTH OF MAY. PRECIPITATION IN NORTH PLATTE BASIN
ABOVE SEMINOE RESERVOIR WAS 57 PERCENT AVERAGE. IN THE NORTH
PLATTE BASIN BETWEEN SEMINOE RESERVOIR AND GUERNSY RESERVOIR
PRECIPITATION WAS 94 PERCENT OF AVERAGE. THE NORTH PLATTE BASIN BELOW
GUERNSY RESERVOIR HAD 77 PERCENT OF AVERAGE PRECIPITATION. THE HIGH
ELEVATIONS OF THE SOUTH PLATTE BASIN HAD 110 PERCENT OF AVERAGE
PRECIPITATION WHEREAS THE PLAINS HAD 90 PERCENT OF AVERAGE
PRECIPITATION.
May 2007 Platte Mean Precip Oct-May WY2007 Platte Mean Precip
STREAMFLOW 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 50 TO 60 PERCENT OF
AVERAGE. STREAM FLOW FOR THE NORTH PLATTE BELOW SEMINOE RESERVOIR ARE
FORECAST TO BE BETWEEN 35 TO 65 PERCENT OF AVERAGE. THE SOUTH PLATTE
BASIN ABOVE SOUTH PLATTE, COLORADO CAN EXPECT ABOUT BETWEEN 80 AND
90 PERCENT OF AVERAGE FLOW. FOR THE REMAINDER OF THE SOUTH PLATTE
BASIN FLOWS ARE EXPECTED TO BE BETWEEN 75 AND 110 PERCENT OF AVERAGE.
North Platte Streamflow Fcst South Platte Streamflow Fcst
STORED WATER IN THE NORTH PLATTE BASIN AS OF JUNE 1 WAS 66
PERCENT OF AVERAGE. THE SOUTH PLATTE BASIN HAD 99 PERCENT OF
AVERAGE STORED WATER.
