Published: June 12,2017
Snow is coating parts of the mountain West for the beginning of June's second full week as an unseasonably cold air mass infiltrates the northwestern United States.
The National Weather Service (NWS) in Reno, Nevada, dubbed the wintry weather pattern "Juneary" in a tweet that showed snow falling as low as 5,800 feet in elevation in California's Sierra Nevada early Monday morning.
Measurable snow was also observed at Lake Tahoe on Monday morning. That only happens in June about every 5 to 10 years, the NWS said.
In the central Nevada town of Austin, up to 10 inches of snow had been reported as of Monday morning.
A trace of wet snow fell in Elko, Nevada, Monday morning, making it one of the latest occurrences of observable snow in records dating to 1889, according to the NWS.
Incline Village, Nevada, measured 3 to 6 inches of snow Sunday into Monday.
Snowfall ForecastCold air has moved in with a strong southward dip in the jet stream, or upper-level trough, that has swept into the Northwest as a result of a weather pattern flip.
This system will swing across the northern Rockies through Tuesday, bringing periods of rain and a few thunderstorms to much of the region and snow to some of the higher elevations. Gusty winds are also expected across much of the West at times early this week.
Temperatures will be 10 to 20 degrees colder than average to begin this week, which means it may be cold enough for slushy accumulations of snow in the northern Rockies through Tuesday, especially at night. Many valley locations won't see highs climb out of the 50s on Tuesday.
(MAPS: Weekly Planner)
Mountain passes are expected to see little impact as the June sun will make it difficult for snow to accumulate on roadways during the day. However, slippery roads are possible with any snow that falls overnight.
Several inches of snow are possible across the highest elevations in northeast Nevada, Idaho, southwest Montana, western Wyoming and northeast Utah into Tuesday. Some locations could pick up more than 6 inches of total snow.
Some snow is even possible down to the valley floors in parts of western Wyoming and in most of Yellowstone and Grand Teton national parks by early Tuesday.
Additional Snowfall Forecast Through Tuesday
The biggest impacts from the snow will be felt by outdoor enthusiasts, especially campers, given the stark contrast in temperatures. Highs will be up to 40 degrees cooler than they were late last week in parts of the northern Rockies, so if you have plans to camp early this week, be prepared for cool and wet weather.
How Rare is This?It's not uncommon to see snow in the higher elevations of the mountain West this time of year. In fact, it can also occur in valley locations.
Kalispell, Montana, averages 0.3 inches of snow in June, based on data from 1981-2010. As much as 5.5 inches were measured in June 1995.
Great Falls, Montana, also averages 0.3 inches in June, but it saw 11.1 inches of snow back in June 1950.
Just last year, snow accumulated in the northern Rockies as late as July. Snow was reported in parts of Wyoming, Montana and Idaho at elevations as low as 6,500 feet.
(MORE: Winter Rudely Interrupts Summer in the Northern Rockies)
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