Turnagain Pass

Good morning. This is Kevin Wright with the Chugach National Forest Avalanche Information Center on Friday, February 10th at 7am. This will serve as a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (this advisory does not apply to highways, railroads, or operating ski areas).

BOTTOM LINE

The danger rating has likely reached CONSIDERABLE above treeline this morning. Only a small amount of snow is forecasted today, but above freezing temperatures and high wind will all contribute to building wind slabs and storm snow problems up high. Below treeline, expect a Moderate danger until the snow or rain builds to significant levels.

AVALANCHE DISCUSSION

We got a sunny break in the weather yesterday that allowed us to see what happened from the latest storm. Wednesday night brought up to 2 inches of snow-water and 1-2 feet of snow with wind and warm temperatures. Rain made it above 2000 feet for a short time period. There were a number of medium to large natural avalanches that happened during the storm. Yesterday cleared in the morning and cooling temperatures quickly stabilized the snowpack. There may have been some buried surface hoar contributing to those avalanches, but we believe much of that concern was destroyed by rain down low and wind up high. As far we can tell, the avalanches from the storm were breaking on new snow only and not stepping into older and deeper layers.

Today, warm temperatures and mild snow and rain are back. A couple inches of snow have fallen in the last several hours this morning and wind is picking up with gusts to the 60s at ridgetops. Avalanche danger is increasing again. The primary concern up high will be storm snow from Wednesday night and today continuing to build. Steeper pockets of wind loaded snow off ridgelines and catchment features could be triggered by people today. Natural avalanches are possible if enough snow builds, and should be expected tonight if the blizzard watch proves correct.

Our avalanche danger currently, and for this entire winter so far, fits into the definition of “Direct Action”. We define Direct Action as avalanches that occur during or immediately after a storm. The alternative to direct action is “delayed action”, when avalanche danger lingers for days or weeks after storms and is almost always associated with buried surface hoar, facets, or CNFAIC Staff persistent weak layers. Direct Action problems are much easier to deal with, because the hazard is short lived and spikes during periods of active stormy weather. We have a simple problem to manage – if it’s stormy, snowy, windy, or warm then stick to green light terrain in the backcountry.

MOUNTAIN WEATHER

The current storm is a Low centered in Prince William Sound. We should get at least a few more inches of snow out of this storm today. Temperatures are rising again, and liquid precip may reach up to 500 feet elevation. Wind this morning is already reaching into the 50s and 60s at ridgetops. It looks like anCNFAIC Staff storm day with poor visibility and difficult travel above treeline.

A blizzard watch has been issued for Turnagain Arm this evening and Saturday. The snowfall is expected to increase tonight and into tomorrow.

CNFAIC Weather Page and the NWS forecast

I will issue the next advisory Saturday morning. If you get out in the backcountry we want to know what you are seeing. Please send us your observations using the button at the top of this page or give us a call at 754-2369. Thanks and have a great day.