Avalanche Advisory for March 14, 2014

The avalanche danger in the west central Montana backcountry is MODERATE.

Natural avalanches are unlikely, human triggered avalanche are possible.

Be mindful of heightened avalanche conditions on sun exposed terrain steeper than 30 degrees during clear weather and remember we are still finding deeply buried weak layers that formed during the cold dry weather earlier this winter.

It is possible to trigger a large avalanche in areas where the snowpack is thin and rocky, where faceted snow has persisted since early winter.

Good morning! This is Steve Karkanen with the West Central Montana Avalanche Center’s backcountry avalanche advisory for Friday, March 14. The avalanche danger rating expires at midnight tonight and does not apply to operating ski areas.

Weather and Snowpack

Since Tuesday, mountain weather has moderated with average SNOTEL temperatures bumping 45 degrees in the afternoon then dropping back into the mid-twenties overnight. This morning, mountain temperatures are in the high twenties with southwest winds into the teens. We have not received any precipitation since Tuesday.

Moderate temperatures and melt freeze cycles are strengthening what has been a troublesome snowpack. It has had the time needed to adjust to the heavy load it received earlier this week and surface conditions should be locked up tight until the sun warms things up again.

All observer reports mention continued strengthening of the deeper weak layers we’ve been talking about. The primary avalanche problem they described seeing yesterday is loose wet snow avalanches during the warm afternoons and whenever the sun is out.

Cornices are huge now and very sensitive. Cornice drops, both intentional and unintentional, are pulling out pockets of snow as they trundle down the mountain.

Weather and Avalanche Forecast

The Missoula Office of the National Weather Service is forecasting a disturbance to move into western Montana today with snow levels lowering to around 4000 feet with the possibility of as much as 6-8 inches of new snow by Saturday morning. High pressure will build Saturday then begin to break down slowly Sunday as another weather disturbance moves into the area.

I expect the avalanche danger to remain similar as this next weather system passes through.

Altoona Lakes Avalanche

On Monday March 10, Peter Maxwell of Missoula died in a large avalanche near Altoona Lakes in the Flint Creek Range northeast of Phillipsburg, MT. Avalanche specialists from the West Central Montana Avalanche Center visited the site and talked with witnesses. A report will be posted in a few days.

Our deepest sympathies are with Peter’s family and friends.