Southern San Juan

Dangerous avalanche conditions develop Monday night into Tuesday. You can trigger an avalanche in the storm snow, and some avalanches may break several feet deep on buried weak layers.

A pair of recent accidents highlight the consequence of triggering a deep avalanche. On Friday, three backcountry skiers triggered and were caught in a large avalanche near Marble on an easterly-facing slope. Sadly one died. You can read the preliminary report here. Sunday afternoon another skier died in an accident in Maroon Bowl, on a northerly-facing slope near Aspen Highlands. You can read this preliminary report here.

An Avalanche Watch is in effect from Tuesday night through Thursday afternoon. Expect very dangerous avalanche conditions. Heavy snowfall and strong winds will produce natural avalanches, and human-triggered avalanches will be very likely. Avoid backcountry avalanche terrain during this time.

For Tuesday, ongoing snowfall and wind will continue to create dangerous avalanche conditions and increasing hazard as the day progresses. You can trigger an avalanche anywhere you find about ten inches or more of new or drifted storm snow. You can also trigger a larger, more dangerous avalanche which breaks on weak layers buried about two to four feet below the storm snow, and avalanches which you trigger in a surface layer may break into these deeper weak layers. Carefully evaluate what is beneath the new snow, and plan your travels to avoid traveling beneath steep slopes at the end of the day. Slopes less than about thirty degrees with no steep terrain above offer safer options.