April 1, 2012 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 90 PERCENT OF AVERAGE. THE SNOW PACK BETWEEN TOSTON
AND FORT PECK, MONTANA WAS 108 PERCENT. THE SNOW PACK IN THE
ST MARY AND MILK RIVER BASINS WAS 112 PERCENT.
MARCH PRECIPITATION ACROSS THE UPPER MISSOURI BASIN WAS ABOVE AVERAGE
TO AVERAGE. BASIN PRECIPITATION SUMMARIES FOR THE MISSOURI BASIN
INCLUDE: MILK ST. MARY, 194 PERCENT; MILK CANADA, 103 PERCENT;
LOWER MILK, 95 PERCENT; ABOVE TOSTON, 133 PERCENT; TOSTON TO
FT. PECK, 112 PERCENT.
March 2012 Upper Missouri Mean Precip Oct-Mar WY2012 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 117 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 102 PERCENT OF AVERAGE SPRING SUMMER
RUNOFF.
Upper Missouri April 1, 2012 Spring and Summer Streamflow Forecasts
OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA: LIMA RESERVOIR
HAD 156 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 110 PERCENT OF
AVERAGE WATER, GIBSON RESERVOIR HAD 40 PERCENT OF AVERAGE STORED
WATER, AND FRESNO RESERVOIR HAD 99 PERCENT OF AVERAGE STORED WATER.
THE MAJOR HYDROELECTRIC RESERVOIRS IN MONTANA (CANYON FERRY AND
FORT PECK) HAD MONTHEND STORAGE IN THE AVERAGE RANGE; 104 AND 101
PERCENT OF AVERAGE WATER, RESPECTIVELY.
Yellowstone Basin
THE HIGH ELEVATION SNOW PACK IN THE YELLOWSTONE BASIN WAS AVERAGE
ON APRIL 1. THE SNOW PACK IN THE UPPER YELLOWSTONE BASIN WAS
92 PERCENT OF AVERAGE. THE SNOW PACKS IN THE WIND, BIGHORN, AND
SHOSHONE BASINS WERE 79, 87, AND 92 PERCENT OF AVERAGE,
RESPECTIVELY. THE SNOW PACKS IN THE TONGUE AND POWDER BASINS WERE
92 AND 87 PERCENT OF AVERAGE, RESPECTIVELY.
PRECIPITATION DURING MARCH WAS MUCH BELOW AVERAGE. THE UPPER
YELLOWSTONE RIVER BASIN RECEIVED 93 PERCENT OF AVERAGE PRECIPITATION.
WHILE THE LOWER YELLOWSTONE BASIN REPORTED 33 PERCENT OF AVERAGE.
THE BIGHORN BASIN RECEIVED 58 PERCENT OF AVERAGE PRECIPITATION
WHILE THE WIND RIVER BASIN RECEIVED 36 PERCENT OF AVERAGE.
THE LITTLE BIGHORN - UPPER TONGUE BASIN RECEIVED 40 PERCENT OF
AVERAGE AND THE POWDER RIVER HAD 14 PERCENT OF AVERAGE PRECIPITATION.
March 2012 Yellowstone Mean Precip Oct-Mar WY2012 Yellowstone Mean Precip
FORECAST STREAM FLOW IN THE YELLOWSTONE BASIN IS NEAR
AVERAGE RANGE FOR THE UPCOMING SPRING AND SUMMER. RUNOFF AT
BILLINGS, MONTANA IS EXPECTED TO BE 96 PERCENT OF AVERAGE. STREAM
FLOW FOR THE WIND-BIGHORN BASIN ABOVE ST. XAVIER, MONTANA IS
FORECAST TO BE ABOUT 70 PERCENT OF AVERAGE. FLOW IN THE
TONGUE BASIN IS EXPECTED TO BE 92 PERCENT OF AVERAGE. FLOWS IN THE
POWDER RIVER ARE EXPECTED TO BE ABOUT 85 PERCENT OF AVERAGE.
MONTHEND STORAGE AT BOYSEN RESERVOIR WAS 108 PERCENT OF AVERAGE.
STORED WATER IN BUFFALO BILL RESERVOIR WAS 116 PERCENT OF AVERAGE.
MONTHEND STORAGE WAS 105 PERCENT OF AVERAGE AT BIGHORN RESERVOIR.
Yellowstone April 1, 2012 Spring and Summer Streamflow Forecasts
Platte Basin
THE HIGH ELEVATION SNOW PACK IN THE UPPER NORTH PLATTE BASIN WAS
57 PERCENT OF AVERAGE ON APRIL 1. THE SNOW PACK IN THE NORTH
PLATTE BASIN BELOW SEMINOE RESERVOIR WAS 76 PERCENT OF AVERAGE.
THE SNOW PACK IN THE SOUTH PLATTE BASIN WAS 60 PERCENT OF AVERAGE.
MARCH PRECIPITATION ACROSS THE PLATTE BASIN WAS MUCH BELOW AVERAGE.
PRECIPITATION DURING MARCH IN THE NORTH PLATTE BASIN ABOVE
SEMINOE RESERVOIR WAS 25 PERCENT OF AVERAGE. IN THE
NORTH PLATTE BASIN BETWEEN SEMINOE RESERVOIR AND GUERNSY RESERVOIR
PRECIPITATION WAS 12 PERCENT OF AVERAGE. THE NORTH PLATTE BASIN
BELOW GUERNSY RESERVOIR HAD LESS THAN 1 PERCENT OF AVERAGE PRECIPITATION.
THE HIGH ELEVATIONS OF THE SOUTH PLATTE BASIN HAD 6 PERCENT OF
AVERAGE PRECIPITATION WHEREAS THE PLAINS HAD 7 PERCENT OF AVERAGE
MARCH PRECIPITATION.
March 2012 Platte Mean Precip Oct-Mar WY2012 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
20 TO 65 PERCENT OF AVERAGE. STREAM FLOWS FOR THE NORTH PLATTE
BELOW SEMINOE RESERVOIR ARE FORECAST TO BE AROUND 45 PERCENT OF
AVERAGE. STREAMS IN THE SOUTH PLATTE BASIN ABOVE SOUTH PLATTE,
COLORADO CAN BE AROUND 45 PERCENT OF AVERAGE FLOW. FOR THE
REMAINDER OF THE SOUTH PLATTE BASIN FLOWS ARE EXPECTED VARY FROM
60 TO 75 PERCENT OF AVERAGE.
STORED WATER IN THE SOUTH PLATTE BASIN WAS 104 PERCENT OF AVERAGE
ON APRIL 1. STORED WATER IN THE NORTH PLATTE BASIN WAS 113
PERCENT OF AVERAGE.
North Platte Streamflow Fcst South Platte Streamflow Fcst
