|Signal Word||Size (D scale)||Simple Descriptor|
|Small||1||Unlikely to bury a person|
|Large||2||Can bury a person|
|Very Large||3||Can destroy a house|
|Historic||4 & 5||Can destroy part or all of a village|
The sunny skies and high pressure that sit over our region will be present again today; clouds may move in tomorrow and a chance for snow exists on Wednesday. Despite the sunshine, chilly and breezy Northerly winds are likely to keep the sun from warming the snow surface too much today, limiting the chance for wet snow avalanches. What this means avalanche-wise is another day with no contributing factors to snowpack instability. We remain in a holding pattern of sorts as the chances for triggering an old hard slab avalanche are becoming more unlikely as time goes on.
The current snowpack has a poor structure with many weak layers that sit 2-4′ below the surface. These layers are composed of facets and buried surface hoar. The slab on top is hard and varies in thickness due to prior wind effect. The snow surface has been beat up by wind and sun over the past three weeks. Although the weak layers continue to adjust and the slab on top is losing its ability to propagate, we are still concerned someone could find just the wrong spot on just the wrong slope and trigger a dangerous avalanche. Places most suspect are thin snowpack zones such as the Girdwood Valley and the South end of Turnagain Pass towards Johnson Pass, Lynx Creek and Summit Lake. Additionally, North and Easterly slopes in general have a thinner pack making them more suspect. Trigger points in this situation are often in thin areas near rocks or in scoured areas along ridges. As always, practice safe travel habits, expose one person at a time and minimize exposure in avalanche terrain.
Although winds are likely to limit surface warming by the sun, keep this on your radar in the afternoon. If the snow heats up enough to become wet and punchy, it’s time to move to another aspect. Photos below are from Portage Valley on Saturday. This close up view on the right is a solar aspect of Maynard Mtn on the North side of Portage Lake. This slope is one of the first to have natural wet avalanches on sunny warm days.
Note the snowfall during March in the chart below. One large storm right before Spring Break that brought 2-3 feet of snow to the region. Since then, only a few inches has fallen and since March 20th, no snow has fallen.
Watch out for cornices along ridgelines. It’s that time of year where cornices will begin to slowly warm during daytime heating, making them easier to break off. As always, give cornices plenty of space and limit exposure underneath them.
Yesterday sunny skies prevailed again over the region. Ridgetop winds were light (5-10mph) with gusts in the 20’s mph from the Northwest. During the day, temperatures warmed to the low 40’sF at sea level and to 30F along ridgetops. Overnight, temperatures have dropped to the teens to the low 20’s at sea level and similar along ridgelines.
Today, Monday, we can expect clear skies again. Ridgetop winds may bump up slightly from the North to the 10-15mph. Temperatures should climb at sea level to near 40F again today and to near 30F along ridgelines.
For Tuesday, clouds may move in ahead of a low-pressure that looks to move into our region from the East on Wednesday. This may also bring a chance for light snowfall on Wednesday. Stay tuned!
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||31||0||0||75|
|Summit Lake (1400′)||30||0||0||30|
|Alyeska Mid (1700′)||31||0||0||70|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||29||NW||9||32|
|04/18/21||Turnagain||Avalanche: Turnagain Pass Road Obs||Andy Moderow|
|04/17/21||Turnagain||Avalanche: Road obs||Johnston-Bloom / Moderow Forecaster|
|04/16/21||Turnagain||Avalanche: Seattle Ridge||Wendy Wagner Forecaster|
|04/16/21||Turnagain||Avalanche: Turnagain Pass, non-motorized side seen from Seattle Ridge||CNFAIC Staff Forecaster|
|04/16/21||Turnagain||Observation: Sunburst||Lance breeding|
|04/15/21||Turnagain||Observation: Tincan||Schauer/ Rothman Forecaster|
|04/13/21||Turnagain||Observation: Turnagain Pass Road Obs||A Schauer Forecaster|
|04/12/21||Turnagain||Observation: Tincan||Johnston-Bloom / Latosuo Forecaster|
|04/10/21||Turnagain||Observation: north sides||lance breeding|
|04/09/21||Turnagain||Observation: Girdwood to Turnagain Road Observations||W Wagner Forecaster|
Status of riding areas across the Chugach NF is managed by the Glacier and Seward Ranger Districts, not avalanche center staff. Riding area information is posted as a public service to our users and updated based on snow depth and snow density to prevent resource damage at trailhead locations. Riding area questions contact: email@example.com
|Area||Status||Weather & Riding Conditions|
This is 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.