Turnagain Pass Avalanche Forecast

The sunny skies and high pressure that sit over our region will be present again today; clouds may move in tomorrow and a chance for snow exists on Wednesday. Despite the sunshine, chilly and breezy Northerly winds are likely to keep the sun from warming the snow surface too much today, limiting the chance for wet snow avalanches. What this means avalanche-wise is another day with no contributing factors to snowpack instability. We remain in a holding pattern of sorts as the chances for triggering an old hard slab avalanche are becoming more unlikely as time goes on.

The current snowpack has a poor structure with many weak layers that sit 2-4′ below the surface. These layers are composed of facets and buried surface hoar. The slab on top is hard and varies in thickness due to prior wind effect. The snow surface has been beat up by wind and sun over the past three weeks. Although the weak layers continue to adjust and the slab on top is losing its ability to propagate, we are still concerned someone could find just the wrong spot on just the wrong slope and trigger a dangerous avalanche. Places most suspect are thin snowpack zones such as the Girdwood Valley and the South end of Turnagain Pass towards Johnson Pass, Lynx Creek and Summit Lake. Additionally, North and Easterly slopes in general have a thinner pack making them more suspect. Trigger points in this situation are often in thin areas near rocks or in scoured areas along ridges. As always, practice safe travel habits, expose one person at a time and minimize exposure in avalanche terrain. 

Although winds are likely to limit surface warming by the sun, keep this on your radar in the afternoon. If the snow heats up enough to become wet and punchy, it’s time to move to another aspect. Photos below are from Portage Valley on Saturday. This close up view on the right is a solar aspect of Maynard Mtn on the North side of Portage Lake. This slope is one of the first to have natural wet avalanches on sunny warm days. 

Note the snowfall during March in the chart below. One large storm right before Spring Break that brought 2-3 feet of snow to the region. Since then, only a few inches has fallen and since March 20th, no snow has fallen. 

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Watch out for cornices along ridgelines. It’s that time of year where cornices will begin to slowly warm during daytime heating, making them easier to break off. As always, give cornices plenty of space and limit exposure underneath them.