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News Release

January 1 Montana Mountain Snowpack Primed for Normal Water Year

Brian Domonkos

Bozeman--December 2012 treated Montana generously, providing above average snowfall across the entire state, according to snow survey data from the USDA Natural Resources Conservation Service (NRCS). The majority of the accumulation came during the beginning of the month, while drier conditions prevailed during the latter half of the month.

SNOTEL (SNOwTELemetry) data indicated Dec. 1 snowpack was near 80 percent of average, but due to an active weather pattern statewide, snowpack ended December just below average. “This is typically the turning point in the snow accumulation season with nearly half of a normal year’s accumulation behind us,” said , NRCS water supply specialist. “Snowpack is currently positioned well for the remainder of the year provided near normal snowfall for the remaining season.”

Generally, precipitation in Montana started off well in October, predominately in the form of rain, yielding to drier conditions in November and even drier during December. The early season rain helped wet soils dehydrated from the summer dry spell and soaked soils to near levels experienced in October 2010.

Since the beginning of the water year on Oct. 1, the mountains of Montana have received nearly 110 percent of average precipitation. The Flathead in Montana has seen nearly 120 percent of average precipitation. The National Weather Service Climate Prediction Center is forecasting above average precipitation for western and central Montana through March. More details and basin specific analyses will follow in the Water Supply Outlook Report later this week.

At the time of this release, the basin snowpack summary reports were not available. These reports included data from both manual snow courses and automated SNOTEL sites. The snow summary table below uses SNOTEL data only from Jan. 1. For detailed and summarized snowpack information, go to

Snow Water Content
River Basin Percent of Average Last Year Percent of Average
Columbia 95 89
Kootenai 107 95
Flathead 94 77
Upper Clark Fork 91 86
Bitterroot 86 97
Lower Clark Fork 90 95
Missouri 101 87
Missouri Headwaters 107 81
-- Jefferson 106 80
-- Madison 107 78
-- Gallatin 108 83
Missouri Mainstem 88 103
-- Headwaters Mainstem 93 106
-- Smith-Judith-Musselshell 93 95
-- Sun-Teton-Marias 82 111
-- Milk (Bearpaw Mtns) 59 54
St. Mary 104 86
St. Mary & Milk 101 84
Yellowstone 94 106
Upper Yellowstone 100 99
Lower Yellowstone 97 112
Statewide 97 94

Most streamflow volume forecasts are also predicted to be near normal come April 1. Some exceptions do exist most notably in the river basins of the Lower Yellowstone and in some Missouri Headwaters basins.

Below are the averaged river basin streamflow forecasts for the period April 1 through July 31. These forecasts assume near normal moisture and runoff conditions January through July.

Streamflow Forecasts
River Basin April to July this Year Percent of Average April to July Last Year Percent of Average
Columbia 103 84
-- Kootenai 117 79
-- Flathead 100 83
-- Upper Clark Fork 103 88
-- Bitterroot 100 91
-- Lower Clark Fork 103 82
Missouri 98 81
-- Jefferson 95 71
-- Madison 105 83
-- Gallatin 96 89
-- Missouri Mainstem 97 80
-- Smith-Judith-Musselshell 102 77
-- Sun-Teton-Marias 103 93
-- Milk --- 79
St. Mary 103 97
Yellowstone 89 99
-- Upper Yellowstone 99 90
-- Lower Yellowstone 80 107
Statewide 98 86

NOTE: The "April-July Last Year Percent of Average" column above is what was forecast last year, NOT what actually occurred.

If you encounter any problems with the files provided on this page, please contact Brian Domonkos at .

For detailed basin streamflow forecast information go to:

Provisional Water Supply Forecasts (TXT; 24 KB)


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