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:  October 19, 2018

 

UPPER MISSOURI BASIN

 

September precipitation across the Upper Missouri Basin was below to above average.
Basin precipitation summaries for the Missouri Basin include: Milk St. Mary,
46 percent; Milk Canada, 76 percent; Lower Milk, 155 percent; above Toston,
42 percent; Toston to Ft. Peck, 105 percent.

Of the four major irrigation reservoirs in Montana; Lima
Reservoir had 171 percent average storage, Clark Canyon was
holding 142 percent of average water, Gibson Reservoir had 72
percent of average stored water, and Fresno Reservoir had
89 percent of average stored water.

The major hydroelectric reservoirs in Montana (Canyon Ferry and
Fort Peck), had monthend storage in the average to above
average range; 101 and 122 percent of average water, respectively.

 

 

YELLOWSTONE BASIN

Precipitation during September was below average. The upper Yellowstone River Basin received 47 percent of average precipitation while the Lower Yellowstone River Basin reported 83 percent of average. The Bighorn Basin received 23 percent of average precipitation while the Wind River Basin received 6 percent of average. The Little Bighorn - Upper Tongue Basin received 75 percent of average and the Powder River had 63 percent of average precipitation.


Monthend storage at Boysen Reservoir was 112 percent of average. Stored water in Buffalo Bill Reservoir was 132 percent of average. Monthend storage was 101 percent of average at Bighorn Reservoir.

 

PLATTE BASIN

 

Precipitation during September in the Upper North Platte Basin was 23 percent of average. In the Lower North Platte Basin, precipitation was 21 percent of average. The North Platte Plains below Guernsey Reservoir had 42 percent. The South Platte Mountains had 56 percent whereas the Plains had 50 percent of average September precipitation.

Stored water in the South Platte Basin was 99 percent of average on October 1.
 

 

PRECIPITATION MAPS
September 2018  WY 2018
September 2018 Precipitation Percent of 1981-2010 Average WY2018 Precipitation as Percent of 1981-2010 Average
September 2018 Basin Mean Precipitation          WY2018 Basin Mean Precipitation
September 2018 MBRFC Basin Mean Precipitation      WY2018 MBRFC Basin Mean Precipitation