Seward & Southern Kenai Mtns

Recent Avalanches:  Widespread avalanche activity occurred this week in the Seward area with two very large storms passing through. The weight of the new snow, rain, and wind caused many large natural storm slab, wind slab, and loose snow avalanches. There were also some very large avalanches observed, which we think failed during the storms on the January facet layer that is now buried up to 5′ deep in some places. Most of these avalanches were observed yesterday, February 22 once the skies cleared and we could finally see the mountains.

Weather Recap: Two huge storms passed over the Kenai Peninsula this week bringing a total of 4-5″ of water or snow water equivalent (SWE) to the mountains. This came in the form of rain to at least 2,000′ and 1-2′ of snow above during the first storm that occurred Monday and Tuesday, February 19 and 20. The next storm was close on the first one’s heels coming in Wednesday afternoon, February 21 and tapering off Thursday morning, February 22. This one was colder bringing snow to sea level and another 2-3′ of snow in the alpine.

Weather Outlook: Temperatures have cooled off as of Friday morning February 23, to 24 F in Seward. Today’s weather looks quiet, sunny with light south to southwest ridgetop winds and temperatures in the Lost Lake area in the 20’s F. Clouds look to build tonight with another weak front approaching. Saturday is forecast to be cool and a bit stormy with temperatures in the low 20’s F and ridgetop winds building to 20 to 30 mph from the northwest with gusts to 45 mph. The mountains could see 2-3″ of new snow by Saturday evening. The system is forecast to move out Saturday night, but the winds should remain in that 20 to 30 mph range from the northwest through Sunday tapering off Sunday evening. Sunday looks to be sunny with temperatures in the single digits F in the morning climbing into the teens F by the afternoon.

New snow slab avalanches on Mount Alice with a big beautiful moon. Photo: Mark Dalpes 2.22.24

New snow slab avalanches on Resurrection South Peak. Photo: Mark Dalpes 2.22.24

With 2-5′ of new snow in the Seward Mountains this week and a few more inches forecast there is plenty of snow to be moved around by the wind this weekend making wind slab avalanches our primary concern. Wind slabs 1-2′ deep will be likely and easy for a person to trigger in places that have been recently loaded. Wind slabs tend to form below ridgelines, on cross-loaded gully features, and on steep rolls. Watch for blowing snow and avoid those places where it is depositing. Wind slabs may feel firm or sound hollow and if you poke your pole or probe in them there will be stiffer snow over softer snow. You can dig a quick hand pit or jump on a small test slope to see how the slab is bonding to the snow beneath. Shooting cracks and whumpfs are clear signs of unstable snow.

Wet loose avalanches: The sun is forecast to come out on Sunday, which could cause some wet loose avalanches especially on steep south facing slopes with alders or rocks poking through the snow. It looks like it will be cool and windy, which can help keep this from happening, but keep your eyes out for “roller balls” or wet balls of snow rolling down the slope. Roller balls are early signs of wet loose avalanches which have a lot of weight to them and can be difficult to escape if you find yourself caught.

Wind blowing off Callisto Peak south of the Seward Zone. Winds this weekend are forecast to come from a similar direction. Photo 2.22.2024

Wet avalanche debris on the east face of Mount Marathon. This slide probably released during the warmer storm on Tuesday Feb. 20. The debris crosses the “Jeep Trail” that passes underneath these large slide paths. Photo 2.21.2024

Here is a close-up view of the debris running over the trail and into the large trees on the right of the photo. Photo submitted anonymously, 2.21.2024

The January facet weak layer we keep talking about is now buried 2-5′ deep in the Seward area. This layer is showing signs that it is strengthening, and we think it is unlikely that the weight of a human would be enough to trigger an avalanche on this layer. Several avalanches were observed after the most recent storm that we believe failed on this layer and they are located in specific places underneath rock bands with steep slopes above.

We have some uncertainty about this in some places because we haven’t been to Carter Lake or Snug Harbor in a couple of weeks. With the recent warm temperatures, we think this layer is strengthening throughout the zone, but the only way to assess this problem is to dig a snowpit and perform stability tests. If you find a layer of more cohesive snow over a layer of weak sugary snow that is a sign of poor structure regardless of test results. It is also important to know that this type of avalanche may not produce any warning signs before releasing. To completely avoid this problem stick to slopes less than 30 degrees.

Large slab underneath rockband that is likely a “persistent slab” avalanche failing on the January facet weak layer. Photo 2.22.24