Anyone looking north toward the Bridger Mountains Friday morning could see fast-moving, heavy clouds rolling into Bozeman.

Soon, a blizzard had settled in. But the storm left as quickly as it came.

A little after 8 a.m. Friday, cell phones buzzed around the Gallatin Valley with an alert for a snow squall. A squall is a localized storm that can bring rapid change in conditions through sleet, rain or, in Bozeman’s case, snow. It lasted about an hour.

Ray Greely, a National Weather Service meteorologist in Great Falls, described it as a heavy snow shower accompanied by heavy wind.

“A snow squall is typically a heavy burst of snow that’s short in nature,” Greely said.

Greely said skies are generally clear before and after a squall, but a whiteout can take place in between. The National Weather Service sends out alerts for snow squalls for this reason.

“People are usually not prepared for what’s coming, and someone could experience deteriorating road conditions with little to no warning,” Greely said.

The weather service advises drivers to reduce speed and turn on their headlights during a snow squall. It warns that roads can become slick quickly. When conditions become severe, Greely said the best option may be to pull over.

Greely said the cell phone alerts are particularly important during high traffic times.

Bozeman residents were alerted to another squall a week ago on Saturday.

“It’s not uncommon in winter in Montana,” Greely said.

The weather services predicts a chance of snow Saturday and Sunday.

Bridger Bowl Ski Area added five inches of new snow Friday. Big Sky Resort added about four inches.

Shaylee Ragar can be reached at sragar@dailychronicle.com or at 582-2607.

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