Forecasters on Thursday ratcheted up predictions for an Arctic weather event next week that has the potential to bring white-out and blizzard conditions to the Flathead Valley and other parts of Western Montana on Sunday.

In a presentation by the National Weather Service’s Missoula office, senior meteorologist Bob Nester said sustained 15- to 30-mile-per-hour winds could produce dangerous wind chills and blizzard-like conditions throughout the region.

“We’re expecting very windy conditions area-wide, not just in the canyons,” Nester said. “This is going to lead to extensive blowing and drifting of snow making travel very difficult.”

Beginning Tuesday, Nester added that a frigid air mass moving through Siberia and into Canada is expected to produce a historic, prolonged cold-weather event.

“What’s important about this event is we really have not had any kind of long-duration, extreme cold-weather event, say five or six days, for 20 years,” he said.

Kalispell could see low temperatures reaching into the negative 20s next week, a threshold that has been crossed just four times since the last event in 1998. For higher-elevation areas like Polebridge and Seeley Lake, lows could reach 40 degrees below zero.

Nester also warned of a substantial frostbite danger as the mercury dips, noting that subzero temperatures can cause frostbite on exposed skin within half an hour. Coupled with 20 mile-per-hour winds, that window of time can drop to 10 minutes.

Next week’s frigid temperatures may break single-day records in some spots, but the weather agency doesn’t expect the event to reach all-time low-temperature records. Kalispell’s lowest-ever recorded temperature of 38 degrees below zero was hit in 1950 — cold, but relatively balmy compared with the minus 52 record set in Butte in 1983.

Snowfall totals on Sunday aren’t expected to exceed a few inches in valleys, but could contribute to blowing snow on the ground as wind speeds pick up.