April 1, 2010 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 BELOW AVERAGE. THE SNOW PACK ABOVE TOSTON, MONTANA
WAS 70 PERCENT OF AVERAGE. THE SNOW PACK BETWEEN TOSTON AND
FORT PECK, MONTANA WAS 70 PERCENT. THE SNOW PACK IN THE ST MARY
AND MILK RIVER BASINS WAS 65 PERCENT.
MARCH PRECIPITATION WAS BELOW AVERAGE ACROSS THE UPPER MISSOURI
BASIN. BASIN PRECIPITATION SUMMARIES FOR THE MISSOURI BASIN
INCLUDE: MILK ST. MARY, 73 PERCENT; MILK CANADA, 34 PERCENT;
LOWER MILK, 27 PERCENT; ABOVE TOSTON, 63 PERCENT; TOSTON TO
FT. PECK, 30 PERCENT.
March 2010 Upper Missouri Mean Precip Oct-Mar WY2010 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 71 PERCENT OF AVERAGE APRIL-SEPTEMBER FLOWS.
RUNOFF IS EXPECTED TO RANGE AROUND 53 PERCENT OF AVERAGE FOR THE
MISSOURI BASIN ABOVE FORT PECK, MONTANA. FORECASTS FOR THE MILK
RIVER BASIN CALL FOR AROUND 50 PERCENT OF AVERAGE SPRING SUMMER
RUNOFF.
Upper Missouri April 1, 2010 Spring and Summer Streamflow Forecasts
OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA: LIMA RESERVOIR
HAD 116 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 111 PERCENT
OF AVERAGE WATER, GIBSON RESERVOIR HAD 52 PERCENT OF AVERAGE STORED
WATER, AND FRESNO RESERVOIR HAD 66 PERCENT OF AVERAGE STORED WATER.
THE MAJOR HYDROELECTRIC RESERVOIRS IN MONTANA (CANYON FERRY AND
FORT PECK) HAD MONTH END STORAGE IN THE AVERAGE TO BELOW AVERAGE
RANGE; 107 AND 87 PERCENT OF AVERAGE WATER, RESPECTIVELY.
YELLOWSTONE BASIN
THE HIGH ELEVATION SNOW PACK IN THE YELLOWSTONE BASIN WAS BELOW
AVERAGE ON MARCH 1. THE SNOW PACK IN THE UPPER YELLOWSTONE BASIN
WAS 70 PERCENT OF AVERAGE. THE SNOW PACKS IN THE WIND, BIGHORN, AND
SHOSHONE BASINS WERE 64, 67, AND 57 PERCENT OF AVERAGE, RESPECTIVELY.
THE SNOW PACKS IN THE TONGUE AND POWDER BASINS WERE 73 AND 84 PERCENT
OF AVERAGE, RESPECTIVELY.
DURING MARCH THE UPPER YELLOWSTONE RIVER BASIN RECEIVED 51 PERCENT
OF AVERAGE PRECIPITATION WHILE THE LOWER YELLOWSTONE BASIN REPORTED
29 PERCENT OF AVERAGE. THE BIGHORN BASIN RECEIVED 77 PERCENT OF
AVERAGE PRECIPITATION WHILE THE WIND RIVER BASIN RECEIVED 110 PERCENT
OF AVERAGE. THE LITTLE BIGHORN - UPPER TONGUE BASIN RECEIVED
43 PERCENT OF AVERAGE AND THE POWDER RIVER HAD 65 PERCENT OF
AVERAGE PRECIPITATION.
FORECAST STREAM FLOW IN THE YELLOWSTONE BASIN IS IN THE BELOW
AVERAGE RANGE FOR THE UPCOMING SPRING AND SUMMER. RUNOFF AT
BILLINGS, MONTANA IS EXPECTED TO BE 62 PERCENT OF AVERAGE, WITH
A PROBABLE RANGE BETWEEN 35 AND 88 PERCENT OF AVERAGE. STREAM
FLOW FOR THE WIND-BIGHORN BASIN ABOVE ST. XAVIER, MONTANA IS
FORECAST TO BE ABOUT 48 PERCENT OF AVERAGE WITH A PROBABLE RANGE
OF 18 TO 97 PERCENT OF AVERAGE FLOW. FLOW IN THE
TONGUE BASIN IS EXPECTED TO BE 49 PERCENT OF AVERAGE WITH
A REASONABLY LIKELY RANGE OF 20 TO 94 PERCENT OF AVERAGE FLOW.
FLOWS IN THE POWDER RIVER ARE EXPECTED TO BE ABOUT 48 PERCENT OF
AVERAGE WITH A REASONABLY LIKELY RANGE OF 19 TO 104 PERCENT OF
AVERAGE.
MONTH END STORAGE AT BOYSEN RESERVOIR WAS 100 PERCENT OF AVERAGE.
STORED WATER IN BUFFALO BILL RESERVOIR WAS 109 PERCENT OF AVERAGE.
MONTH END STORAGE WAS 116 PERCENT OF AVERAGE AT BIGHORN RESERVOIR.
Yellowstone April 1, 2010 Spring and Summer Streamflow Forecasts
Platte Basin
THE HIGH ELEVATION SNOW PACK IN THE UPPER NORTH PLATTE BASIN WAS
86 PERCENT OF AVERAGE ON APRIL 1. THE SNOW PACK IN THE NORTH
PLATTE BASIN BELOW SEMINOE RESERVOIR WAS 93 PERCENT OF AVERAGE.
THE SNOW PACK IN THE SOUTH PLATTE BASIN WAS 83 PERCENT OF AVERAGE.
MARCH PRECIPITATION ACROSS THE PLATTE BASIN WAS AVERAGE TO ABOVE
AVERAGE. PRECIPITATION IN FEBRUARY IN THE NORTH PLATTE BASIN
ABOVE SEMINOE RESERVOIR WAS 94 PERCENT OF AVERAGE. IN THE NORTH
PLATTE BASIN BETWEEN SEMINOE RESERVOIR AND GUERNSY RESERVOIR
PRECIPITATION WAS 167 PERCENT OF AVERAGE. THE NORTH PLATTE BASIN
BELOW GUERNSY RESERVOIR HAD 117 PERCENT OF AVERAGE PRECIPITATION.
THE HIGH ELEVATIONS OF THE SOUTH PLATTE BASIN HAD 139 PERCENT OF
AVERAGE PRECIPITATION WHEREAS THE PLAINS HAD 94 PERCENT OF AVERAGE
MARCH PRECIPITATION.
March 2010 Platte Mean Precip Oct-Mar WY2010 Platte Mean Precip
STREAM FLOW IN THE PLATTE BASIN IS FORECAST TO BE BELOW AVERAGE
DURING THE UPCOMING SPRING AND SUMMER. RUNOFF FOR STREAMS ABOVE
SEMINOE RESERVOIR ARE EXPECTED TO BE ABOUT 55 TO 90 PERCENT OF
AVERAGE. STREAM FLOWS FOR THE NORTH PLATTE BELOW SEMINOE
RESERVOIR ARE FORECAST TO BE 36 TO 100 PERCENT OF AVERAGE. STREAMS
IN THE SOUTH PLATTE BASIN ABOVE SOUTH PLATTE, COLORADO CAN EXPECT
ABOUT 80 PERCENT OF AVERAGE FLOW. FOR THE REMAINDER OF THE SOUTH
PLATTE BASIN FLOWS ARE EXPECTED TO BE ABOUT 70 TO 80 PERCENT OF
AVERAGE.
STORED WATER IN THE SOUTH PLATTE BASIN WAS 102 PERCENT OF AVERAGE
ON APRIL 1. RESERVOIRS IN THE NORTH PLATTE BASIN WERE HOLDING
136 PERCENT OF AVERAGE WATER.
North Platte Streamflow Fcst South Platte Streamflow Fcst
