In the Flathead Range and Glacier Park, the snowpack took a hard hit last weekend and still needs time to recover.   Use caution: You can trigger an avalanche that breaks several feet thick and surprisingly wide on early-season weak layers.  You are most likely to trigger a slide from a shallow, rocky area or a steep rollover. Default to planar, lower angle terrain if your snowpack assessments give you uncertainty.  

In the Swan Range, the snowpack is generally stable. Signs of instability have been sparse this month and the bulk of last weekend's precipitation went north of the Swan. In isolated areas, the potential to trigger an avalanche that breaks several feet thick remains a concern. Stay off of Santa's "Naughty List": ride one at a time, carry rescue gear, and if your buddy's sled gets stuck on a steep slope, let them wrestle it out on their own.  

Approach steep terrain with a critical eye. If your uncertainty is high, keep your slope angles low. You can still trigger persistent weak layers from shallow, rocky areas or convex slopes above about 6,000 feet. Signs of instability, like shooting cracks and collapses, may not always be clear. They vary from slope to slope and across the region. Simple, uniform terrain is the safest bet.

Don't mistake a yellow light for a green. The higher you go, the greater the likelihood of triggering dense wind slabs on leeward or cross-loaded slopes. Smaller avalanches may step down to deeper weak layers, resulting in dangerously large slides. With high freezing levels, loose wet avalanches are likely on very steep terrain. Beware of shooting cracks and collapsing in stiffer snow and watch for rollerballs where the surface is wet.

Dangerous conditions persist where there is good snow coverage above about 5,000 feet. The higher you go, the greater the likelihood of triggered or natural wind slabs on leeward or cross-loaded slopes. Smaller avalanches may step down to deeper weak layers, resulting in dangerously large slides near the Divide. With high freezing levels, loose wet avalanches are likely on very steep terrain. Beware of shooting cracks and collapsing in stiffer snow and watch for rollerballs where the surface is wet.

Dangerous conditions exist at upper elevations, thanks to a combination of new and drifted snow and rapidly warming temperatures. At mid-elevations, rain and above freezing temperatures have made wet snow avalanches possible on steep slopes. You can ride safe in these complex conditions by keeping it simple. Avoid being on or under steep slopes with more than about a foot of new and/ or drifted snow. At mid elevations, steer clear of steep slopes with gloppy wet snow. 

Dangerous conditions are developing as a vigorous storm brings heavy snowfall, powerful winds, and rising freezing levels to the Flathead Range and Lake McDonald area. Because natural and remotely triggered avalanches are possible, avoid being on or under steep slopes, where new and drifted snow are forming dense slabs. These slabs are a hazard in themselves; they are also overloading weak snow buried deep in the snowpack. The danger will rise through the day, and may remain elevated Saturday. 

Very dangerous conditions are developing as a vigorous storm brings heavy snowfall, powerful winds, and rising freezing levels to the Whitefish Range. Because natural and remotely triggered avalanches are likely, avoid being on or under steep slopes, where new and drifted snow are forming dense slabs. These slabs are a hazard in themselves and are also overloading weak snow buried deep in the snowpack. The danger will rise through the day, and may remain elevated Saturday. 

Near upper elevations, the danger of triggering slides several feet deep lingers. Choose planar slopes away from rocky outcroppings to reduce your risk of disturbing a sleeping giant. As a winter storm arrives today, the danger of triggering avalanches involving new snow will rise. Steer clear of steep slopes with more than 8 inches of new and drifted snow.

An AVALANCHE WATCH in effect for the Whitefish Range. The danger is expected to rise to HIGH tomorrow or Saturday.  

As the snowpack continues to gain strength from the last load of snow, mixed messages of instability persist. Though only a handful of avalanche reports have come in since the recent storm, whumpfing collapses continue to show signs that weak layers that have yet to adjust. Recent collapses highlight the lingering threat of triggering a slab up to several feet thick in steep terrain as you transition near and into upper elevations.

As the snowpack continues to gain strength, mixed messages of instability persist. Though only a handful of avalanche reports have come in since the recent storm, whumpfing collapses show signs that weak layers that have yet to adjust. Recent collapses highlight the lingering threat of triggering a slab up to several feet thick in steep terrain as you transition into upper elevations.

Stable weather is allowing the snowpack to catch its breath after an active December.  Convexities and thin, rocky areas at upper elevations are most likely to get you in trouble: Slabs up to several feet thick still have the potential to be triggered on early-season crusts and surface hoar layers.  

Lots of observations yesterday highlight the snowpack is quieting down as stability improves.  Use caution as you gain elevation towards and above alpine terrain where the threat of triggering a high consequence avalanche is most acute.  Conditions are safer the lower you go: Softer slabs, stronger weak layers, and plenty of vegetation anchors make for improved stability.

Lots of observations yesterday highlight the snowpack is quieting down as stability improves.  Use caution as you gain elevation near and into alpine terrain where the threat of triggering a high consequence avalanche is most acute.  The safest riding is at mid-elevations: Softer slabs, stronger weak layers, and plenty of vegetation anchors make the threat of an avalanche much more isolated.