Good morning. This is Chris Engelhardt with the Chugach National Forest Avalanche Information Center on Thursday, April 12th 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).
This will be our final week of daily avalanche advisories, ending April 15th. We will be issuing one mid-week update on Wednesday and one weekend update on Saturday mornings through April 30th. Observations from our staff/public will be kept current and checking the photos/observations page regularly will be the best place to find up to date information for the last two weeks of April.
The danger remains at MODERATE today and very well could jump into the CONSIDERABLE level for wet avalanches on aspects seeing lots of sun today. We currently have had our second night of minimally freezing temp’s, hovering just at 32F at 3800ft, and clear sunny conditions are anticipated for today. Also, we continue to have a MODERATE danger for persistent slab avalanches on northerly slopes above 2000′ where buried surface hoar exists 6-20” deep.
The conditions are starting to become prime time for larger wet avalanche events to start happening. Bright clear sunny days have been baking sunny aspects and the warm air that has moved into the area has kept night time temperatures just barely below freezing at ridge tops and above freezing at and below tree line. There was several reports from Turnagain pass yesterday of “slushy” conditions on south aspects and even “sticky” conditions on north aspects. Actively moving wet point releases were observed widely. We did not get a real hard freeze and crust over the past two nights, so be aware of increasingly unsupportable conditions and dangerous potential for hot shedding slopes. This could also be the ultimate hammer blow for cornices that grew very large from the big winter of snows and are just waiting to cut loose. And yes, surface hoar layers still reside on northerly aspects above 2000′ and continue to trigger persistent slabs of 1-2 feet deep
Primary Concern – Wet Avalanches, Glide Avalanches and Cornices
Warm overnight temperature (above freezing at the mid elevations) for the last two nights hasn’t provided a good refreeze of the snow pack. Timing will be everything right now in finding supportable and softer conditions to ski and ride on. In all likelihood finding the “golden hour” of supportable yet carvable crusts will be earlier in the day and will have a much shorter window of being good (both for skiing and safety). Travel routes really need to be well thought out well in advance to anticipate and take into account rapid warming of the slopes. Most importantly, make sure you have a good route out from your mission at the end of the day when temperatures and sun will be peaking, and sunny slopes have had all day to loosen up. Minimizing or avoiding all together travel below south slopes today would be in your best interest. If you’re literally falling through the snow on skis, or your machine is starting to get mired in saturated unsupportable snow, it’s time to get out of there. Avoid stepping in or on, traveling beneath, or hanging around Cornices, Glide cracks, or terrain traps.
Secondary Concern – Persistent Slabs
The persistent slab resting on surface hoar on north aspects continues to live with us every day. Even though becoming harder to find and less tender, it still exists and continues to be found by skiers sniffing out dry powder. The story continues to be the same in dealing with this issue. Evaluate your terrain choice and decide if you can handle a potentially fast moving 6-18” slab failing on skier weight. Committing terrain with exposure will be risky. Any north slope that shows no sign of avalanching naturally should be looked at with a critical eye.
The unsurpassed beauty and vastness of south-central Alaska can truly be appreciated on days like we have been having of late. Bright sunny skies, light winds and warm temps have been the overall way of life the past 4 days. Temperatures reached the 40’s yesterday at ridge tops and have stayed just at or below 32F at night. Winds were very calm through the day yesterday, last night, and are expecting to remain absent today. Continued sun, calm winds and no precipitation are supposed to continue to prevail into the near future. Extra water, sun screen, ball cap, and a CAMERA have become essential items the past few days.
CNFAIC Weather Page and the NWS forecast
Wendy will issue the next advisory tomorrow 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.