January 1, 2025 Spring and Summer Streamflow Forecasts
Upper Missouri Basin
The high elevation snow pack in the Upper Missouri Basin as of January 1
was below average. The snow pack in the St. Mary Basin was 94 percent,
and the Milk River Basin was 67 percent.
December precipitation across the Upper Missouri Basin was below average.
Basin precipitation summaries for the Missouri Basin include: Milk St. Mary,
69 percent; Milk Canada, 88 percent; Lower Milk, 102 percent; above Toston,
63 percent; Toston to Ft. Peck, 88 percent.
December 2024 Upper Missouri Mean Precip Oct-Dec WY2025 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 58 percent of average
April-September flows. Runoff is expected to range around
73 percent of average for the Missouri Basin above Fort Peck,
Montana.
Upper Missouri January 1, 2025 Spring and Summer Streamflow Forecasts
Of the four major irrigation reservoirs in Montana; Lima
Reservoir had 102 percent average storage, Clark Canyon was
holding 93 percent of average water, Gibson Reservoir had 26
percent of average stored water, and Fresno Reservoir had
27 percent of average stored water.
Yellowstone Basin
The high elevation snow pack in the Yellowstone Basin was below toabove average
on January 1. The snow pack in the Upper Yellowstone Basin was 55 percent
of average. The snow packs in the Wind, Bighorn, and Shoshone Basins were 71,
69, and 63 percent of average, respectively. The snow packs in the Tongue
and Powder basins were 66 and 60 percent of average, respectively.
Precipitation during December was below to above average. The upper Yellowstone
River Basin received 54 percent of average precipitation while the
Lower Yellowstone River Basin reported 144 percent of average. The
Bighorn Basin received 43 percent of average precipitation while the
Wind River Basin received 64 percent of average. The Little Bighorn -
Upper Tongue Basin received 54 percent of average, and the Powder River
had 65 percent of average precipitation.
December 2024 Yellowstone Mean Precip Oct-Dec WY2025 Yellowstone Mean Precip
Forecast stream flow in the Yellowstone Basin is below average
for the upcoming Spring and Summer. Stream flow for the
Yellowstone River above Sidney, Montana is forecast to be about
60 percent of average. Flow in the Tongue Basin is expected to be
60 percent of average. Flows in the Powder River are expected
to be about 40 percent of average.
Monthend storage at Boysen Reservoir was 108 percent of average.
Stored water in Buffalo Bill Reservoir was 106 percent of average.
Monthend storage was 102 percent of average at Bighorn Reservoir.
Yellowstone January 1, 2025 Spring and Summer Streamflow Forecasts
Platte Basin
The high elevation snow pack in the Upper North Platte Basin was
89 percent of average on January 1. The snow pack in the North Platte
Basin below Seminoe Reservoir was 79 percent of average. The snow
pack in the South Platte Basin was 99 percent of average.
Precipitation during December in the Upper North Platte Basin was 75
percent of average. In the Lower North Platte Basin, precipitation
was 52 percent of average. The North Platte Plains below Guernsy
Reservoir had 8 percent. The South Platte Mountains had 56
percent whereas the Plains had 7 percent of average December
precipitation.
December 2024 Platte Mean Precip Oct-Dec WY2025 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 72 percent of average. Streams in the South Platte
Basin above South Platte, Colorado can expect 88 percent
of average flow. For the remainder of the South Platte
basin, flows are expected near 87 percent.
Stored water in the South Platte Basin was 112 percent of average
on January 1.
North Platte Streamflow Fcst South Platte Streamflow Fcst
