After a sunny weekend of generally stable conditions the weather change today is not expected to affect the avalanche danger, as not much snow or wind is forecast. However, it will be important to pay attention if conditions change. The snow surfaces are not ideal for new snow bonding to the old snow. This will become a real concern when we do get snow accumulation.
Finding an isolated slab especially in upper elevation terrain in Girdwood, Portage or Placer is not completely out of the question. This part of the advisory area received more snow in the last storm. There has been one known human triggered avalanche that failed in the facets below the new snow, which was last Thursday in the Placer Valley. With colder temperatures and no additional loading observations and snowpack tests have been pointing towards a stable snowpack.
Low danger does not mean no danger. Practice good travel habits, such as exposing one person at a time, watching your partners and grouping up in safe zones are key ways to minimize risk. Ease into steep terrain and factor in the consequences should you encounter one of the following:
The next buried weak layer??? Surface hoar on a melt-freeze crust, 1-19-19. Photo: Troy Tempel
South of Turnagain – Johnson Pass/Summit Lake zone: A poor snowpack structure exists in these areas. Multiple mid-pack weak layers of facets and buried surface hoar have been found as well as a facet/crust combination in the bottom of the snowpack. No recent avalanche activity and calm weather has allowed the pack to slowly adjust. However, it still important to evaluate the terrain and snowpack. Upper elevation terrain with hard, wind-affected snow over the buried weak layers is the most suspect.
Yesterday: Sunshine and clear skies with some valley fog. Temperatures ranged from single digits to high teens. Winds were easterly 5-15 mph. Overnight clouds moved in and temperatures increased to the high teens and 20Fs. Winds bumped up slightly gusting into the 20s.
Today: Mostly cloudy skies and a chance of snow showers. Winds will be easterly 5-15 mph with gusts into the 20s. Temperatures will be in the 20Fs. A chance of snow is forecast overnight with steady temperatures and similar winds.
Tomorrow: Tomorrow’s weather looks to be very similar to today and then the chance of precipitation bumps up overnight into Wednesday. There is warm air associated with the southerly flow pushing into the area and may bring some liquid precipitation to the lower elevations. The overall storm track is still uncertain. Stay tuned and think cold thoughts!
*Seattle Ridge weather station was heavily rimed and the anemometer (wind sensor) was destroyed. We are currently working to replace it.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||18||0||0||50|
|Summit Lake (1400′)||7||0||0||21|
|Alyeska Mid (1700′)||18||0||0||38|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||19||*N/A||*N/A||*N/A|