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 20, 2023


 Upper Missouri Basin

November precipitation across the Upper Missouri Basin was below average. Basin precipitation summaries for the Missouri Basin include: Milk St. Mary, 69 percent; Milk Canada, 56 percent; Lower Milk, 70 percent; above Toston, 43 percent; Toston to Ft. Peck, 63 percent. 

Of the four major irrigation reservoirs in Montana; Lima Reservoir had 148 percent average storage, Clark Canyon was holding 162 percent of average water, Gibson Reservoir had 41 percent of average stored water, and Fresno Reservoir had 45 percent of average stored water.

Yellowstone Basin 

Precipitation during November was below average. The upper Yellowstone River Basin received 42 percent of average precipitation while the Lower Yellowstone River Basin reported 23 percent of average. The Bighorn Basin received 77 percent of average precipitation while the Wind River Basin received 128 percent of average. The Little Bighorn - Upper Tongue Basin received 24 percent of average and the Powder River had 38 percent of average precipitation.

Monthend storage at Boysen Reservoir was 107 percent of average. Stored water in Buffalo Bill Reservoir was 104 percent of average. Monthend storage was 100 percent of average at Bighorn Reservoir.


Platte Basin 

Precipitation during November in the Upper North Platte Basin was 48 percent of average.  In the Lower North Platte Basin, precipitation was 59 percent of average.  The North Platte Plains below Guernsy Reservoir had 62 percent.  The South Platte Mountains had 67 percent whereas the Plains had 54 percent of average November precipitation.

Stored water in the South Platte Basin was 121 percent of average on December 1.


November 2023  WY 2024
November 2023 Precipitation Percent of 1991-2020 Average WY2024 Precipitation as Percent of 1991-2020 Average
November 2023 Basin Mean Precipitation          WY2024 Basin Mean Precipitation
November 2023 MBRFC Basin Mean Precipitation      WY2024 MBRFC Basin Mean Precipitation