National Weather Service United States Department of Commerce

Missouri Basin River Forecast Center
Water Supply Statement
Issued in cooperation with the Natural
Resources Conservation Service
Issued:  April 12, 2006

 

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.

 

March 2006 Yellowstone Mean Precip                                                Oct-Mar WY2006 Yellowstone Mean Precip
 

STREAM FLOW IN THE YELLOWSTONE BASIN IS FORECAST TO BE AVERAGE TO BELOW AVERAGE DURING THE UPCOMING SPRING AND SUMMER. RUNOFF AT BILLINGS, MONTANA IS EXPECTED TO BE 102 PERCENT OF AVERAGE, WITH A PROBABLE RANGE BETWEEN 76 AND 128 PERCENT OF AVERAGE. STREAM FLOW FOR THE WIND-BIGHORN BASIN ABOVE ST. XAVIER, MONTANA IS FORECAST TO BE 80 TO 82 PERCENT OF AVERAGE WITH A PROBABLE RANGE OF 54 TO 109 PERCENT OF AVERAGE FLOW IN SUB-BASINS. FLOW IN THE TONGUE BASIN IS EXPECTED TO BE 71 TO 76 PERCENT OF AVERAGE WITH A REASONABLY LIKELY RANGE OF 30 TO 112 PERCENT OF AVERAGE FLOW. FLOWS IN THE POWDER RIVER ARE EXPECTED TO BE ABOUT 74 PERCENT OF AVERAGE WITH A REASONABLY LIKELY RANGE OF 29 TO 120 PERCENT.

MONTH END STORAGE WAS AT 98 PERCENT OF AVERAGE AT BOYSEN RESERVOIR IN WYOMING, 100 PERCENT OF AVERAGE AT BUFFALO BILL RESERVOIR IN WYOMING, AND 100 PERCENT OF AVERAGE AT BIGHORN RESERVOIR ON THE WYOMING/MONTANA BORDER.

RUNOFF DURING MARCH IN THE YELLOWSTONE RIVER WAS 103 PERCENT OF THE 1971 TO 2000 AVERAGE AT CORWIN SPRINGS AND 81 PERCENT OF THAT AVERAGE AT BILLINGS.
 

 

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.

 

PRECIPITATION MAPS
March 2006  WY 2006
March 2006 Precipitation Percent of 1971-2000 Average WY2006 Precipitation as Percent of 1971-2000 Average
March 2006 Basin Mean Precipitation          WY2006 Basin Mean Precipitation
March 2006 MBRFC Basin Mean Precipitation      WY2006 MBRFC Basin Mean Precipitation