Avalanche Advisory for Monday, January 8, 2018

Huntington Ravine will reach Considerable and Moderate avalanche danger. Central Gully will reach Considerable avalanche danger. Careful snowpack evaluation and cautious route finding are essential. All other areas will reach Moderate avalanche danger. Heightened avalanche conditions will develop on specific terrain features.

 Tuckerman Ravine will reach Considerable and Moderate avalanche danger today. Sluice, Lip, Center Bowl, and Chute will reach Considerable avalanche danger. Careful snowpack evaluation and cautious route finding are essential. Lobster Claw, Right, Left, and Hillman’s Highway will reach Moderate avalanche danger. Heightened avalanche conditions will develop on specific terrain features. Lower Snowfields and Little Headwall are the exceptions with a Low rating. Watch for unstable snow on isolated terrain features.

 AVALANCHE PROBLEM: New wind slabs building later today and tonight are our primary concern. The few inches of snow will be transported by ideal wind speeds to create sensitive slabs in lee areas by the end of the day. If we receive the higher end of forecast snowfall, human triggered avalanches should become likely in areas receiving the greatest wind loading by the end of the forecast period. Your likelihood of triggering an avalanche in the dense and supportable older surface slab that precedes today’s storm remains unlikely in all but highest rated areas.

WEATHER: Snow showers which began last night should intensify slightly through the day. Mixed forecasts lead us to expect 3” or more of snow accumulation today on W wind of around 60 mph that will increase slightly into tonight. Temperatures have been slowly climbing since yesterday and will likely hit the upper teens or warmer this afternoon. Snowfall is forecast to taper off late tonight to at least a partial clearing tomorrow afternoon. Wind should remain constant with only slightly cooler temperatures tomorrow.

SNOWPACK: Today’s snow falls on a largely firm surface layer that has been hammered by sustained wind speeds in the neighborhood of 100 mph over the past few days. Potential for you to trigger an avalanche in the older layer remains possible at best, and avoiding travel on or below any significant new wind slabs developing today will provide a safer alternative as hazards increase. It’s worth noting snow total forecasts for today vary widely and that today’s danger ratings reflect potential for a wind slab avalanche problem developing through the forecast period which ends at midnight tonight. If we see the lower end of forecast snowfall our avalanche danger will not increase to as great a degree. That said, blowing snow and limited visibility could hamper your ability to judge wind slab development in terrain above you.

You will see changes to the advisory in the coming weeks and months as we try to find more effective ways to present the avalanche and mountain safety message in an efficient and helpful way. Today’s danger rating section purposely lacks likelihood of avalanche information which you will find in the problem section or in the North American Public Avalanche danger scale posted on kiosks or at the link on this page below the map.

2018-1-8