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Snowmelt Peak Streamflow Dates Forecast Table

Snowmelt Peak Streamflow Dates Forecast Table

***2016 Streamflow Data will be available after May 1st, 2016.***

The snowmelt peak dates below are predictions for the 2015 water year and are computed using May 7th, 2015, data. The dates below are predictions for snowmelt driven runoff and does not account for rain driven streamflow runoff occurring in the past, present or future. Peak streamflow forecasts ranges and date averages below are for daily average flow (cubic feet per second) and do not represent instantaneous peaks.  

Peak date forecasts for streamflow points affected by upstream reservoirs were not calculated with known reservoir operations other than what has typically occurred in the past. 

Columbia River Basin
Watershed 1981-2010 Average
Bitterroot River near Darby 5/22
Bitterroot River at Missoula 5/24
Blackfoot River near Bonner 5/21
Clark Fork River above Missoula 5/25
Clark Fork River at St. Regis 5/25
Clark Fork River below Missoula 5/25
Clark Fork River near Drummond 5/25
Como Reservoir Inflow 5/22
Fisher River near Libby 5/15
Little Blackfoot River near Garrison 5/14
Lower Willow Creek Reservoir Inflow 5/13
Middle Fork Flathead River near West Glacier 5/20
Middle Fork Rock Creek near Phillipsburg 5/24
Mill Creek near Niarada 5/5
Nevada Creek near Helmville 5/19
North Fork Flathead River near Columbia Falls 5/22
Prospect Creek at Thompson Falls 5/15
South Fork Flathead River above Twin Creeks 5/21
South Fork Jocko River near Arlee 5/17
Swan River near Big Fork 5/24
Thompson River near Thompson Falls 5/16
Tobacco River near Eureka 5/20
Yaak River near Troy 5/15


Missouri River Basin
Watershed 1981-2010 Average Snowmelt Peak Date
Badger Creek near Browning 5/22
Big Hole River below Big Lake Creek at Wisdom 6/1
Big Hole River near Melrose 5/29
Boulder River near Boulder 5/22
Clark Canyon Reservoir Inflow 6/5
Cut Bank Creek near Browning 5/20
Dearborn River near Craig 5/18
Gallatin River near Gateway 6/2
Gallatin River at Logan 6/1
Gibson Reservoir Inflow 5/24
Hebgen Reservoir Inflow 5/22
Hyalite Reservoir Inflow 6/2
Jefferson River near Three Forks 5/30
Lima Reservoir Inflow 5/16
Madison River near West Yellowstone 5/21
Marias River near Shelby 5/23
Missouri River at Toston 6/2
Musselshell River at Harlowton 5/24
Musselshell River near Martinsdale 5/21
North Fork Musselshell River near Delpine 5/25
Ruby Reservoir Inflow 5/27
Sheep Creek near White Sulphur Springs 5/24
Smith River below Eagle Creek near Fort Logan 5/21
Swift Reservoir Inflow 5/23
Two Medicine River near Browning 5/22
Willow Creek near Harrison 6/1


Saskatchewan River Basin
Watershed 1981-2010 Average Snowmelt Peak Date
Lake Sherburne Inflow 5/22
St. Mary River at International Boundary ***


Yellowstone River Basin
Watershed 1981-2010 Average Snowmelt Peak Date
Boulder River near Big Timber 6/4
Big Goose Creek near Sheridan Wyoming 5/26
Clarks Fork River near Belfry 6/4
Cooney Reservoir inflow 5/31
Little Bighorn River near Hardin 5/28
Little Goose Creek near Bighorn Wyoming 5/25
West Rosebud near Roscoe 6/9
Powder River at Moorehead 5/22
Shields River near Livingston 5/27
Stillwater River near Absarokee 6/5
Tongue River at Dayton Wyoming 5/26
Tongue River Reservoir Inflow 5/24
Yellowstone River at Billings 6/7
Yellowstone River at Corwin Springs 6/2
Yellowstone River at Lake Outlet 6/25
Yellowstone River at Livingston 6/4