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
JANUARY 1 WAS MAINLY AVERAGE TO SLIGHTLY BELOW AVERAGE. THE SNOW
PACK ABOVE TOSTON, MONTANA WAS 82 PERCENT OF AVERAGE. THE SNOW
PACK BETWEEN TOSTON AND FORT PECK, MONTANA WAS 85 PERCENT. THE
SNOW PACK IN THE ST MARY AND MILK RIVER BASINS WAS 79 PERCENT.
DECEMBER PRECIPITATION WAS MAINLY BELOW AVERAGE ACROSS
THE UPPER MISSOURI BASIN. BASIN PRECIPITATION SUMMARIES FOR THE
MISSOURI BASIN INCLUDE: MILK ST. MARY, 50 PERCENT; MILK CANADA, 95
PERCENT; LOWER MILK, 53 PERCENT; ABOVE TOSTON, 70 PERCENT; TOSTON
TO FT. PECK, 64 PERCENT.
Dec 2006 Upper Missouri Mean Precip Oct-Dec WY2007 Upper Missouri Mean Precip
STREAM FLOW IN THE UPPER MISSOURI BASIN IS FORECAST TO BE AVERAGE
DURING THE UPCOMING SPRING AND SUMMER. THE ST. MARY RIVER IS FORECAST
TO HAVE 94 PERCENT OF AVERAGE APRIL-SEPTEMBER FLOWS. RUNOFF IS
EXPECTED TO RANGE AROUND 90 PERCENT OF AVERAGE FOR THE MISSOURI BASIN
ABOVE FORT PECK, MONTANA. FORECASTS FOR THE MILK RIVER BASIN CALL FOR
AROUND 100 PERCENT OF AVERAGE SPRING SUMMER RUNOFF.
OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA: LIMA RESERVOIR
HAD 128 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 72 PERCENT OF
AVERAGE WATER, GIBSON RESERVOIR HAD 93 PERCENT OF AVERAGE STORED
WATER, AND FRESNO RESERVOIR HAD 80 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; 92 AND 56 PERCENT OF AVERAGE WATER, RESPECTIVELY.
THE U.S. GEOLOGICAL SURVEY LONG TERM GAGING STATION, ON THE MARIAS
RIVER NEAR SHELBY, MONTANA HAD AN ESTIMATED 95 PERCENT OF AVERAGE
RUNOFF IN DECEMBER.
Yellowstone Basin
THE HIGH ELEVATION SNOW PACK IN THE YELLOWSTONE BASIN WAS BELOW
AVERAGE ON JANUARY 1. THE SNOW PACK IN THE UPPER YELLOWSTONE
BASIN WAS 77 PERCENT OF AVERAGE. THE SNOW PACKS IN THE WIND,
BIGHORN, AND SHOSHONE BASINS WERE 71, 77, AND 70 PERCENT OF
AVERAGE, RESPECTIVELY. THE SNOW PACKS IN THE TONGUE AND POWDER
BASINS WERE 80 AND 70 PERCENT OF AVERAGE, RESPECTIVELY.
PRECIPITATION DURING THE MONTH OF DECEMBER WAS BELOW AVERAGE TO
MUCH BELOW AVERAGE. THE RANGE WAS FROM 80 PERCENT OF AVERAGE IN
THE BIGHORN RIVER BASIN TO 31 PERCENT OF AVERAGE IN THE POWDER
RIVER BASIN.
Platte Basin
THE HIGH ELEVATION SNOW PACK IN THE UPPER NORTH PLATTE BASIN WAS
103 PERCENT OF AVERAGE. THE SNOW PACK IN THE NORTH PLATTE BASIN
BELOW SEMINOE RESERVOIR WAS 94 PERCENT OF AVERAGE. THE SNOW PACK
IN THE SOUTH PLATTE BASIN WAS 130 PERCENT.
PRECIPITATION ACROSS THE PLATTE BASIN WAS MAINLY
ABOVE AVERAGE FOR THE MONTH OF DECEMBER, WITH AS MUCH AS 380
PERCENT OF AVERAGE FALLING ACROSS THE SOUTH PLATTE PLAINS. OTHER
PRECIPITATION SUMMARIES FOR THE PLATTE BASIN INCLUDE: UPPER NORTH
PLATTE, 85 PERCENT; LOWER NORTH PLATTE, 121 PERCENT; NORTH PLATTE
PLAINS, 272 PERCENT.
December 2006 Platte Mean Precip Oct-Dec WY2007 Platte Mean Precip