MTPR

March Precipitation Below Average Across Much Of Western Montana

Apr 4, 2019

Below-normal precipitation last month combined with warmer seasonal temperatures nibbled around the edges of Montana’s snowpack, but it could have been a lot worse.

It turns out that February’s bitter cold and record snowfall had an important upside. It bought Montana’s snowpack a little extra time during what turned out to be a very dry March.

"Most places across the state saw below average precipitation, and our mountain SNOTEL sites, which measure our snowpack, actually experienced record low precipitation for the month of March," says Lucas Zukiewicz, a water supply specialist with the Bozeman-based Natural Resources Conservation Service.

"There wasn’t any good precip news. I’d imagine that the only good news we have is that February was such a big month across the state that it’s helped us to insulate ourselves from this below normal snowfall for the month; but that doesn’t hold up everywhere."
 
Northwest Montana, for example, hasn’t been so lucky this winter. The Kootenai and Flathead river basins did not benefit from a lot of early winter snow.
 
"Those areas are actually below normal for snowfall at this time and water-year precipitation totals. So, if we look at October first through current, those areas are fairly dry with regards to snowpack and precipitation."

West Central Montana and the Bitterroots report slightly above-normal snowpack for early March. Barring any unusually warm weather, forecasts are calling for generally average snowmelt and streamflow conditions there.

Snowpack percentages in the mountains supplying Central Montana river basins are near normal, while southern basins report above normal totals on April 1.

Current snow water equivalent basin percentage of normal, April 4, 2019.
Credit Natural Resources Conservation Service

The National Weather Service’s Climate Prediction Center is calling for increased chances of above average temperatures across Western Montana this month, and increased chances for precip across the state’s southern tier.

"On May first we should know when we made that change to snowmelt in those western basins, as well as what they peaked at. East of the Divide we still have a little bit of time. Really, we’re just going to have to wait and see what plays out."

Spring mountain snowfall and valley precipitation play an important role in runoff for any given year.