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:  December 21, 2022


 Upper Missouri Basin

November precipitation across the Upper Missouri Basin was mainly above average. Basin precipitation summaries for the Missouri Basin include: Milk St. Mary, 64 percent; Milk Canada, 110 percent; Lower Milk, 116 percent; above Toston, 170 percent; Toston to Ft. Peck, 136 percent. 

Of the four major irrigation reservoirs in Montana; Lima Reservoir had 56 percent average storage, Clark Canyon was holding 82 percent of average water, Gibson Reservoir had 34 percent of average stored water, and Fresno Reservoir had 79 percent of average stored water.

Yellowstone Basin 

Precipitation during November was above average. The upper Yellowstone River Basin received 112 percent of average precipitation while the Lower Yellowstone River Basin reported 135 percent of average. The Bighorn Basin received 130 percent of average precipitation while the Wind River Basin received 144 percent of average. The Little Bighorn - Upper Tongue Basin received 184 percent of average and the Powder River had 96 percent of average precipitation.

Monthend storage at Boysen Reservoir was 102 percent of average. Stored water in Buffalo Bill Reservoir was 101 percent of average. Monthend storage was 93 percent of average at Bighorn Reservoir.


Platte Basin 

Precipitation during November in the Upper North Platte Basin was 100 percent of average.  In the Lower North Platte Basin, precipitation was 93 percent of average.  The North Platte Plains below Guernsy Reservoir had 69 percent.  The South Platte Mountains had 80 percent whereas the Plains had 50 percent of average November precipitation.

Stored water in the South Platte Basin was 90 percent of average on December 1.


November 2022  WY 2023
November 2022 Precipitation Percent of 1981-2010 Average WY2023 Precipitation as Percent of 1981-2010 Average
November 2022 Basin Mean Precipitation          WY2023 Basin Mean Precipitation
November 2022 MBRFC Basin Mean Precipitation      WY2023 MBRFC Basin Mean Precipitation