|Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
|Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
|Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential.
|Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
|Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain.
|Likelihood of Avalanches
|Natural and human-triggered avalanches unlikely.
|Natural avalanches unlikely; human-triggered avalanches possible.
|Natural avalanches possible; human-triggered avalanches likely.
|Natural avalanches likely; human-triggered avalanches very likely.
|Natural and human-triggered avalanches certain.
|Avalanche Size and Distribution
|Small avalanches in isolated areas or extreme terrain.
|Small avalanches in specific areas; or large avalanches in isolated areas.
|Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.
|Large avalanches in many areas; or very large avalanches in specific areas.
|Very large avalanches in many areas.
Turnagain Pass: There was only one new avalanche reported yesterday, which looked to have failed early in the morning or on Thursday night. It was a natural avalanche on a southwest-facing wind loaded slope at 4000′, just to the east of Pastoral. There was another avalanche in the same bowl that looked to be a few days old.
|Size (D scale)
|Unlikely to bury a person
|Can bury a person
|Can destroy a house
|4 & 5
|Can destroy part or all of a village
Well it looks like most of this round of snow is going to miss us, but the winds have already found their way into the area. Winds began ramping up last night, blowing 15-20 mph out of the east with gusts of 35-40 mph. We are expecting to see that trend continue through the day, with sustained easterly winds at 15-30 mph and gusts of 30-50 mph. The snow totals are looking meager in our advisory area, with 1-2″ possible in Girdwood, a trace to an inch in Turnagain Pass, and 3-5″ in the Portage and Placer Valleys. With the strong winds and low snow totals, the main issue to focus on will be fresh wind slabs that began forming last night and will continue to grow during the day.
Human-triggered avalanches will be likely with natural avalanches possible on steep, wind loaded slopes at and above treeline, and they are expected to get big enough to bury a person. Even though we are not expecting to get much new snow today, there is already plenty of snow on the ground that is ready to be blown into sensitive slabs. The middle elevations between 1000′ and 2500′ that remained sheltered during the most recent wind event will have the most slab-building ammunition, but strong winds at ridgetops will be able to find some soft snow to work with. Be cautious around steep slopes near ridgelines, on convex rolls, and in gullies, as these will be the most likely terrain features to harbor fresh slabs. As always, be on the lookout for warning signs of unstable snow like shooting cracks, collapsing, and fresh avalanche activity. We are still tracking multiple crusts buried in the upper 2-3′ of the snowpack. For now it appears they have gone dormant, but it is an issue to keep in mind as the snowpack sees more loading today.
Cornices: This round of strong winds will once again be at work making large cornices even larger. Keep plenty of space from the edge as you travel along ridgelines, since these are notorious for breaking farther back from ridgelines than expected. As winds continue blowing today, it will also be important to limit time spent traveling below cornices, since they may break naturally and have the potential to trigger wind slabs forming below.
Click HERE for a link to the video below describing the snowpack near Pastoral if it doesn’t load in your browser.
Yesterday: The day started with clouds, but skies cleared throughout the day with mostly sunny skies in the afternoon. Winds were calm with variable gusts for most of the day, until they started picking up to 15-20 mph yesterday evening around 9 p.m. Temperatures were in the upper teens to low 20’s F for most of the day, and warmed overnight to the upper 20’s to mid 30’s F. There was no precipitation during the day, and weather stations are picking up a trace of snow this morning.
Today: Easterly winds are expected to continue to ramp up today, with sustained speeds of 15-30 mph with gusts of 30-50 mph. It is looking like Girdwood could see 1-2″ of snow during the day, with a trace to 1″ at Turnagain Pass and 3-5″ in the Portage and Placer valleys. The snow line should stay around 600′. High temperatures are expected to stay in the upper 20’s to mid 30’s F during the day under mostly cloudy skies with some pockets of sun poking through.
Tomorrow: Winds are expected to shift back to the northwest late tonight, dropping back down to 1-5 mph. Overnight low temperatures should be in the mid to upper 20’s F, with daytime highs in the upper 20’s F. We might see a trace of snow before this system breaks up. Skies are looking to be mostly cloudy again tomorrow, with some pockets of sun possible. Expect to see another round of active weather early next week, with more precipitation possible starting Monday night.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)
|Snow Depth (in)
|Center Ridge (1880′)
|Summit Lake (1400′)
|Alyeska Mid (1700′)
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)
|Wind Avg (mph)
|Wind Gust (mph)
|Seattle Ridge (2400′)
|Observation: Seattle Ridge
|John Sykes Forecaster
|Observation: Kickstep NE Bowl
|Observation: TinCan Backdoor/ Center Ridge
|AAS L1 Turnagain
|Avalanche: Lynx Creek
|Observation: Turnagain, Seattle, Mt Ascension
|Silverton Mountain Guides
|Observation: Tincan Trees
|Dalpes/Thamm/ Schauer Forecaster
|Observation: Seward Highway across from Johnson Pass TH
|Avalanche: Base of Seattle Ridge
|Troy Tempel, Thomas Lees, .Josh Bollaert, Damian Naquin