Missouri River Basin Streamflow Fcst as of May 1, 2015 Missouri River Basin Mountain Snowpack as of May 1, 2015
Upper Missouri Basin
THE HIGH ELEVATION SNOW PACK IN THE UPPER MISSOURI BASIN AS OF
MAY 1 WAS BELOW AVERAGE. THE SNOW PACK ABOVE TOSTON,
MONTANA WAS 71 PERCENT OF AVERAGE. THE SNOW PACK BETWEEN TOSTON
AND FORT PECK, MONTANA WAS 59 PERCENT. THE SNOW PACK IN THE
ST MARY AND MILK RIVER BASINS WAS 47 PERCENT.
APRIL PRECIPITATION ACROSS THE UPPER MISSOURI BASIN RANGED FROM
AVERAGE TO BELOW AVERAGE. BASIN PRECIPITATION SUMMARIES FOR THE MISSOURI
BASIN INCLUDE: MILK ST. MARY, 45 PERCENT; MILK CANADA, 37 PERCENT;
LOWER MILK, 81 PERCENT; ABOVE TOSTON, 80 PERCENT; TOSTON TO
FT. PECK, 67 PERCENT.
April 2015 Upper Missouri Mean Precip Oct-Apr WY2015 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 77 PERCENT OF AVERAGE APRIL-SEPTEMBER
FLOWS. RUNOFF IS EXPECTED TO RANGE AROUND 43 PERCENT OF AVERAGE
FOR THE MISSOURI BASIN ABOVE FORT PECK, MONTANA.
Upper Missouri May 1, 2015 Spring and Summer Streamflow Forecasts
OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA: LIMA RESERVOIR
HAD 99 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 85 PERCENT OF
AVERAGE WATER, GIBSON RESERVOIR HAD 129 PERCENT OF AVERAGE STORED
WATER, AND FRESNO RESERVOIR HAD 125 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; 106 AND 117 PERCENT OF AVERAGE WATER, RESPECTIVELY.
Yellowstone Basin
THE HIGH ELEVATION SNOW PACK IN THE YELLOWSTONE BASIN WAS BELOW AVERAGE
ON MAY 1. THE SNOW PACK IN THE UPPER YELLOWSTONE BASIN WAS
71 PERCENT OF AVERAGE. THE SNOW PACKS IN THE WIND, BIGHORN, AND
SHOSHONE BASINS WERE 64, 69, AND 60 PERCENT OF AVERAGE,
RESPECTIVELY. THE SNOW PACKS IN THE TONGUE AND POWDER BASINS WERE
82 AND 73 PERCENT OF AVERAGE, RESPECTIVELY.
PRECIPITATION DURING MARCH WAS AVERAGE TO BELOW AVERAGE. THE UPPER
YELLOWSTONE RIVER BASIN RECEIVED 74 PERCENT OF AVERAGE PRECIPITATION
WHILE THE LOWER YELLOWSTONE BASIN REPORTED 61 PERCENT OF AVERAGE.
THE BIGHORN BASIN RECEIVED 73 PERCENT OF AVERAGE PRECIPITATION
WHILE THE WIND RIVER BASIN RECEIVED 98 PERCENT OF AVERAGE.
THE LITTLE BIGHORN - UPPER TONGUE BASIN RECEIVED 82 PERCENT OF
AVERAGE AND THE POWDER RIVER HAD 78 PERCENT OF AVERAGE PRECIPITATION.
April 2015 Yellowstone Mean Precip Oct-Apr WY2015 Yellowstone Mean Precip
FORECAST STREAM FLOW IN THE YELLOWSTONE BASIN IS BELOW
AVERAGE RANGE FOR THE UPCOMING SPRING AND SUMMER. STREAM
FLOW FOR THE WIND-BIGHORN BASIN ABOVE ST. XAVIER, MONTANA IS
FORECAST TO BE ABOUT 40 PERCENT OF AVERAGE. FLOW IN THE
TONGUE BASIN IS EXPECTED TO BE 76 PERCENT OF AVERAGE. FLOWS IN THE
POWDER RIVER ARE EXPECTED TO BE ABOUT 50 PERCENT OF AVERAGE.
MONTHEND STORAGE AT BOYSEN RESERVOIR WAS 127 PERCENT OF AVERAGE.
STORED WATER IN BUFFALO BILL RESERVOIR WAS 148 PERCENT OF AVERAGE.
MONTHEND STORAGE WAS 107 PERCENT OF AVERAGE AT BIGHORN RESERVOIR.
Yellowstone May 1, 2015 Spring and Summer Streamflow Forecasts
Platte Basin
THE HIGH ELEVATION SNOW PACK IN THE UPPER NORTH PLATTE BASIN WAS
66 PERCENT OF AVERAGE ON MAY 1. THE SNOW PACK IN THE NORTH
PLATTE BASIN BELOW SEMINOE RESERVOIR WAS 61 PERCENT OF AVERAGE.
THE SNOW PACK IN THE SOUTH PLATTE BASIN WAS 96 PERCENT OF AVERAGE.
APRIL PRECIPITATION ACROSS THE PLATTE BASIN WAS ABOVE
AVERAGE. PRECIPITATION IN THE NORTH PLATTE BASIN ABOVE SEMINOE RESERVOIR
WAS 87 PERCENT OF AVERAGE. IN THE NORTH PLATTE BASIN BETWEEN SEMINOE
RESERVOIR AND GUERNSY RESERVOIR PRECIPITATION WAS 155 PERCENT OF AVERAGE.
THE NORTH PLATTE BASIN BELOW GUERNSY RESERVOIR HAD 190 PERCENT OF AVERAGE
PRECIPITATION. THE HIGH ELEVATIONS OF THE SOUTH PLATTE BASIN HAD 157
PERCENT OF AVERAGE PRECIPITATION WHEREAS THE PLAINS HAD 214 PERCENT OF AVERAGE
MARCH PRECIPITATION.
April 2015 Platte Mean Precip Oct-Apr WY2015 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
50 PERCENT OF AVERAGE. STREAM FLOWS FOR THE NORTH PLATTE
BELOW SEMINOE RESERVOIR ARE FORECAST TO BE 25 PERCENT OF
AVERAGE. STREAMS IN THE SOUTH PLATTE BASIN ABOVE SOUTH PLATTE,
COLORADO CAN EXPECT 95 PERCENT OF AVERAGE FLOW. FOR THE
REMAINDER OF THE SOUTH PLATTE BASIN FLOWS ARE EXPECTED NEAR
90 PERCENT OF AVERAGE.
STORED WATER IN THE SOUTH PLATTE BASIN WAS 113 PERCENT OF AVERAGE
ON MAY 1. STORED WATER IN THE NORTH PLATTE BASIN WAS 101
PERCENT OF AVERAGE.
North Platte Streamflow Fcst South Platte Streamflow Fcst
