Heavy snow engulfs high elevations of Idaho and Montana ahead of summer solstice

Heavy snow blanketed high elevations of Idaho and Montana from Tuesday into Wednesday, June 16 into 17, 2020. The unusual winter-like conditions occurred just days before the summer solstice, which will take place this weekend. While not terribly unusual, since snow can still fall during the early and late summer in the northern Rockies, there were some impressive snowfall totals, including a report of 43.2 cm (17 inches) near Darkhorse Lake just west of the Continental Divide in Montana, NWS said.

In Idaho, the Blaine County Sheriff's Office said "a Felony Warrant has been issued for Mother Nature for Illegal Dumping" as up to 25 cm (10 inches) of snow fell north of Galena Summit while 15 cm (6 inches) was registered at the southern area.

Deputies also had to deal with vehicles stuck on roadways. 

"It's only three days from the summer solstice but it's snowing up in Idaho's high country," the National Weather Service (NWS) in Boise reported as it posted images from Bogus Basin and Redfish Lake, showing accumulated snow.

"It looks like about 5 cm (2 inches) has accumulated."

New daily precipitation records were also set on Wednesday as Idaho Falls picked up 22.86 mm (0.91 inches), smashing the previous record of 15.24 mm (0.6 inches) set in 1964.

Challis also registered 24.13 mm (0.95 inches), breaking the old record of 17.78 mm (0.7 inches) set in 2018.

In the neighboring state of Montana, forecasters at the NWS Missoula said snow levels stayed above 1 828 m (6 000 feet), but accumulating snowfall stayed out of inhabited valleys.

Winter storm warnings were issued for elevations above 1 676 m (5 500 feet) in the southwestern region, and forecasters warned of travel difficulties on mountain roads. 

NWS Missoula noted that snow amounts at their SNOTEL stations reached up to 48.3 cm (19 inches), which is more in one day that had been recorded in the past 30 to 40 years for those particular locations.

According to AccuWeather Senior Meteorologist Bill Deger, the late-spring snowfall was due to a chilly area of low pressure that traversed the Northwest.

"While not terribly unusual, since snow can still fall during the early and late summer in the northern Rockies, there were some impressive snowfall totals, including a report of 43.2 cm (17 inches) near Darkhorse Lake just west of the Continental Divide in Montana," he added.

"The heaviest totals look like they were above 2 134 m (7 000 feet)."

Featured image credit: Blaine County Sherriff