BOZEMAN, Mont., Feb. 7, 2018 – The snowpack across Montana remains in good shape starting the month of February with all basins in the state at near to above normal for the date. In fact, Montana is the only state in the 12 western U.S. states where the USDA Natural Resources Conservation Service measures snowpack in which all basins in the state have at least normal snowpack conditions on Feb 1.
“La Nina weather patterns this year have favored the northern tier states across the western U.S and so far Montana and Wyoming have been the big winners,” said Lucas Zukiewicz, NRCS water supply specialist for Montana.”
Building on a strong early season snowpack, the month of January provided consistent moisture to the basins in the state, although the approaching storms from the West Coast came in with above normal temperatures. Many mountain locations were 3 to 7 degrees F above average for the month of January, which resulted in a mix of snow and rain through the month west of the Divide. Mid-month the rain levels reached mid to high elevations, raining over an inch on the mountain snowpack in some locations.
“Even with the warmer than average weather, the mountain snowpack stood strong through the month with little to no discharge at water yielding elevations,” Zukiewicz said. “The water was stored in the snowpack until runoff in the spring, thanks to a cold snowpack in place from the month of December.”
The snowfall for the overall water year (October 1st – current) hasn’t been record breaking in most locations, but is has been above normal, according to NRCS data. However, Zukiewicz pointed out there are some records in central and southwest Montana. One SNOTEL site set a new Feb 1 record (Frohner Meadow SNOTEL) and eight other SNOTEL sites and snowcourses are recording the second highest snow water equivalent totals for the date. Percentage wise, the best snowpack in the state can be found in the Upper Clark Fork (140% of normal), Missouri Mainstem near Helena (148%), Upper Yellowstone (148%) and Gallatin River basins (129%).
All of this amounts to great information to water users in the state, but a healthy dose of caution is still warranted. “Getting complacent, or bragging about snowpack at the beginning of February would be like bragging about leading Daytona halfway through the race,” Zukiewicz said “It doesn’t matter where you are halfway through it, it matters where you’re at when it wraps up”.
Snowpack typically peaks across the state during April or May, depending on which region in the state you’re in. The coming months are critical for water supply, and in many basins east of the Divide the months of March, April and May typically provide significant precipitation.
“Should La Nina and associated weather patterns continue to favor the state with above normal snowfall, or even normal snowfall from this point, water supply could be more than adequate for irrigation and recreation this summer,” Zukiewicz said “But, if the pattern takes a turn, and the snow faucet shuts off, the prospects of our water supply would be diminshed.”
Snowpack will continue to be closely monititored through the spring by the NRCS. The next snowpack and water supply update will be issued during the first week in March.
Monthly Water Supply Outlook Reports can be found at the website below after the 5th business day of the month: