Montana Rivers Are Rising Quickly After Near-Record Temps In May
The federal government’s latest snowpack report is out, and heading into summer it’s a mixed bag for Montana.
May’s first two weeks saw near to slightly-below average temperatures in Montana’s higher elevations, as well as cool air and above-normal precipitation in western Montana’s river basins. Eastern Montana also received fairly normal precip.
Lucas Zukiewicz, a water Supply Specialist with the Bozeman-based Natural Resources Conservation Service, says that helped preserve the state’s mountain snowpack.
"We had a major change, though, happen during the last week of the month, where we saw gradually increasing temperatures from pretty much the 24th or 25th through the end of the month."
Zukiewicz says most NRCS snow-reporting sites across the state recorded near, if not record-setting, high temperatures.
"So we saw rapid snow melt from the snowpack during that last week which is one of those reasons we saw such big increases in our river volumes during this last week."
One example, river flows in the Gallatin River Basin quickly reached 7,000 cubic feet per second, which is nearly double its normal peak flow for the year. That’s a sign that in some locations what’s left of our mountain snowpack is rapidly peeling away.
"The Bitterroot, the Jefferson, the Madison and the Gallatin have really seen the most exacerbated melt during this last week. We’re seeing snowpack totals which, if we’d look back toward the beginning of the third week of May, were near normal or slightly below in the Jefferson and Madison, but above normal in the Bitterroot and the Gallatin. When we look at them for this date, they've dropped 20 to 30 or even 40-percent of normal for June first."
Elsewhere in the state, snowpack remains near to slightly above normal.
The National Oceanic and Atmospheric Administration’s Climate Prediction Center is calling for above-average temperatures this summer and generally below normal precipitation.