Dangerous backcountry avalanche conditions exist across Northwest Montana due to recent mountain rainfall and unseasonably warm temperatures.

The Flathead Avalanche Center on Monday issued an avalanche warning for all mountain ranges in the forecast area. Large, wet natural slides were likely.

“Look above you while traveling today, even on uptracks, snowmobile trails and snow-covered roads that normally feel safe,” Flathead Avalanche Center forecaster Blase Reardon warned Monday. “Warm temperatures and rain are increasing the potential for destructive, dangerous avalanches that break 1 to 4 feet deep in the snowpack, on weak snow around old crusts.”

Warm air from the southwest has kept mountain temperature readings above freezing for the last two days, with nearly half an inch of rain reported at some locations. Monday’s freezing level was expected to soar to nearly 10,000 feet in elevation — higher than most mountain peaks in the region.

“While people often talk about a ‘January thaw’ in the Flathead, this is something,” Reardon commented.

Natural avalanches were reported over the weekend in the Red Meadow area north of Whitefish. Even low-elevation slopes were showing signs of instability, with Reardon reporting small avalanche debris piles on the Whitefish Trail near Lion Mountain.

The warm trend and elevated snow levels are expected to last through mid-week. The National Weather Service in Missoula cautioned commuters of the potential for standing water and ponding on roads as the valley snowpack melts.

A cold front Friday will transition rain back to snow, with valley high temperatures in the low 30s on Saturday and Sunday.