Turnagain Pass

Mid-March definitely came in like a lion with all the crazy weather and then March went out like an overheated lamb… Yesterday was the warmest day the advisory area has seen yet. Today should be very similar. Not only are the mid-elevations expected to see wet avalanches, we could see wet avalanche activity on sunny slopes in the high Alpine. Wet loose avalanches will be the most likely, but wet/moist slabs are possible.  The snowpack has already seen many days of a springtime melt-freeze pattern in the low and mid-elevations and with clear skies we did get a freeze overnight. However, with the intensity of the sun and the warm temperatures should be paying close attention to the potential for natural avalanches occurring in the afternoon/evening on solar aspects as crust break down and slopes get mushy. 

A safe day in the mountains includes planning ahead. Don’t be an April Fool! Know the terrain you are traveling on and under and if it will be affected by the sun. The boot test is a great way to assess how the daytime warming is, or is not, affecting the surface. If your boot easily sinks into mushy wet snow, it’s time to get onto shaded slopes or off the one you are on and well away from any runouts. Wet loose avalanches can start small from a person pushing soft wet snow as they ski or ride. If the terrain is large enough, this small slide can entrain snow and turn into a large and unmanageable avalanche. 

CORNICES: Cornices are very large and direct sunshine will destabilize them. A cornice fall has the potential to trigger an avalanche on the slope below and could break farther back than expected. 

Temperatures on Sunburst (3800′) over the last week.  Note the high temperatures yesterday and the lower RH indicating clear skies at night allowing for a solid freeze. 

The avalanche danger on steep slopes on the southern end of the compass will increase to CONSIDERABLE this afternoon/evening. Play the aspects for the best conditions and to stay safe!

 Avalanche carnage on the southerly slopes of Tincan and in the Library. Avalanches from the past week and the storm avalanche cycle the week prior.

Glide cracks are appearing throughout the advisory area and avalanching daily. Avoid traveling under glide cracks! Fresh glides avalanches were observed yesterday at 1:30 pm on Seattle Ridge and one was observed in motion at 4:30 pm on Tincan. The Seattle Ridge full depth avalanche that hit the uptrack Saturday is likely a glide that did not have a crack present before releasing; making our current avalanche situation more unpredictable. Remember, glides can release even if a hard surface crust is present (unlike the wet loose and wet slab avalanche problems). Many cracks are opening up in popular terrain and keep an eye out for them. 

Fresh glide avalanches observed at 1:30 pm yesterday, 3-31-19. These ran over old glide avalanches that released last week. 

 Glide avalanche that released on the uptrack on Saturday at 5:30 pm, 3-30-19. Photo: Travis Smith

South of Turnagain in Summit Lake and areas in the interior Kenai Peninsula have a very poor snow structure with variety of old weak layers in the mid pack (facets and buried surface hoar.) Triggering a persistent slab 2-3’ deep as slopes warm in the afternoon sun is possible at the upper elevations. The avalanche seen on Butch Mtn. in Summit Lake last week is a good reminder that sunny hot days can surprise us! Keep in mind deeper weak layers could be lurking in these areas and sunlit slopes are the most suspect.