At a Glance

Several inches of snow are possible in the northern Rockies on Tuesday.Snow coated the higher elevations of California, Nevada and northeast Utah on Monday.

Snow is coating parts of the mountain West for the beginningof 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 inCalifornia's Sierra Nevada early Monday morning.

Measurable snow was also observed at Lake Tahoe on Monday morning. Thatonly 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.

A webcam at Gilmore Summit in Lemhi County, Idaho, showed snow falling there early Tuesday morning.

Snowfall Forecast

Cold 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, bringingperiods of rain and a few thunderstorms to much of the region and snow to some of the higher elevations.

(MAPS: )

Several inches of snow arepossible across the highestelevationsin northeast Utah, Idaho, southwest Montana andwestern Wyoming on Tuesday. Some locations could pick up more than 6 inches of total snow.

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.

Slippery roads arepossible with any snow that falls on high-mountain passes in the northern Rockies.

MORE ON WEATHER.COM: Montana, Wyoming Snow – July27, 2015