RUNOFF FOR MOST STREAMS IN THE MISSOURI BASIN ARE FORECAST TO BE AVERAGE TO BELOW AVERAGE. THE HIGH ELEVATION SNOW PACK IN THE MISSOURI BASIN IS NEAR AVERAGE THIS TIME OF THE YEAR. PRECIPITATION IN THE MISSOURI BASIN WAS AVERAGE TO ABOVE EXCEPT FOR THE UPPER YELLOWSTONE, WIND AND BIGHORN BASINS.
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 AVERAGE. THE SNOW PACK ABOVE TOSTON, MONTANA WAS 106 PERCENT OF AVERAGE. THE SNOW PACK BETWEEN TOSTON AND FORT PECK, MONTANA WAS 102 PERCENT. THE SNOW PACK IN THE ST MARY AND MILK RIVER BASINS WAS 95 PERCENT.
MARCH PRECIPITATION ABOVE TOSTON WAS BELOW AVERAGE WITH 82 PERCENT OF NORMAL. FROM TOSTON TO FT. PECK PRECIPITATION WAS ABOVE AVERAGE AT 143 PERCENT OF NORMAL. THE ST. MARY RIVER BASIN WAS BELOW NORMAL WITH 63 PERCENT AND THE MILK RIVER BASIN EXPERIENCED ABOVE NORMAL PRECIPITATION WITH 153 PERCENT OF NORMAL.
Mar 2006 Upper Missouri Mean Precip Oct-Mar WY2006 Upper Missouri Mean Precip
AVERAGE STREAM FLOW IS FORECAST ACROSS THE UPPER MISSOURI BASIN DURING THE UPCOMING SPRING AND SUMMER. THE ST. MARY RIVER IS FORECAST TO HAVE 91 PERCENT OF AVERAGE APRIL-SEPTEMBER FLOWS. RUNOFF IS EXPECTED TO RANGE AROUND 105 PERCENT OF AVERAGE FOR THE MISSOURI BASIN ABOVE FORT PECK, MONTANA. FORECASTS FOR THE MILK RIVER BASIN CALL FOR AROUND 85 PERCENT OF AVERAGE SPRING/SUMMER RUNOFF.
OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA: LIMA RESERVOIR HAD 107 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 70 PERCENT OF AVERAGE WATER, GIBSON RESERVOIR HAD 30 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; 86 AND 61 PERCENT OF AVERAGE WATER, RESPECTIVELY.
AS INDICATED BY THE U.S. GEOLOGICAL SURVEY LONG TERM STATIONS, THE MARIAS RIVER NEAR SHELBY, MONTANA HAD AN ESTIMATED 57 PERCENT OF AVERAGE RUNOFF IN MARCH.
Yellowstone Basin
THE HIGH ELEVATION SNOW PACK IN THE YELLOWSTONE BASIN WAS MOSTLY ABOUT AVERAGE ON APRIL 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 85, 84, AND 78 PERCENT OF AVERAGE, RESPECTIVELY. THE SNOW PACKS IN THE TONGUE AND POWDER BASINS WERE 82 AND 99 PERCENT OF AVERAGE, RESPECTIVELY.
PRECIPITATION DURING THE MONTH OF MARCH WAS ABOUT 57 PERCENT OF AVERAGE IN THE WIND RIVER BASIN ABOVE BOYSEN RESERVOIR, 75 PERCENT OF AVERAGE IN THE UPPER YELLOWSTONE BASIN, 76 AND 94 PERCENT OF AVERAGE IN THE BIGHORN AND LITTLE BIGHORN BASINS, RESPECTIVELY, 83 PERCENT OF AVERAGE IN THE POWDER-TONGUE BASINS, AND 156 PERCENT OF AVERAGE IN THE LOWER YELLOWSTONE BASIN.
Platte Basin
THE HIGH ELEVATION SNOW PACK IN THE UPPER NORTH PLATTE BASIN WAS 110 PERCENT OF AVERAGE ON APRIL 1. THE SNOW PACK IN THE NORTH PLATTE BASIN BELOW SEMINOE RESERVOIR WAS 102 PERCENT OF AVEAGE. THE SNOW PACK IN THE SOUTH PLATTE BASIN WAS 107 PERCENT. PRECIPITATION, DURING MARCH, IN NORTH PLATTE BASIN ABOVE SEMINOE RESERVOIR WAS 137 PERCENT AVERAGE.
PRECIPITATION IN THE NORTH PLATTE BASIN BETWEEN SEMINOE RESERVOIR AND GUERNSY RESERVOIR WAS 109 PERCENT OF AVERAGE. THE NORTH PLATTE BASIN BELOW GUERNSY RESERVOIR HAD 175 PERCENT OF AVERAGE PRECIPITATION. THE HIGH ELEVATIONS OF THE SOUTH PLATTE BASIN HAD 90 PERCENT OF AVERAGE PRECIPITATION WHEREAS THE PLAINS HAD 115 PERCENT OF AVERAGE PRECIPITATION.
March 2006 Platte Mean Precip Oct-Mar WY2006 Platte Mean Precip
STREAM FLOW IN THE PLATTE BASIN ARE FORECAST TO BE SLIGHTLY ABOVE AVERAGE DURING THE UPCOMING SPRING AND SUMMER. RUNOFF FOR STREAMS ABOVE SEMINOE RESERVOIR ARE EXPECTED TO BE BETWEEN 105 AND 125 PERCENT OF AVERAGE. STREAM FLOW FOR THE NORTH PLATTE BELOW SEMINOE RESERVOIR IS FORECAST TO BE BETWEEN 75 TO 115 PERCENT OF AVERAGE. THE SOUTH PLATTE BASIN ABOVE SOUTH PLATTE, COLORADO CAN EXPECT ABOUT 115 TO 120 PERCENT OF AVERAGE FLOW. FOR THE REMAINDER OF THE SOUTH PLATTE BASIN FLOWS ARE EXPECTED TO BE BETWEEN 100 AND 115 PERCENT OF AVERAGE.
STORED WATER IN THE NORTH PLATTE BASIN AS OF APRIL 1 WAS 68 PERCENT OF AVERAGE. THE SOUTH PLATTE BASIN HAD 94 PERCENT OF AVERAGE STORED WATER.