Over the past several weeks snowfall has come in small doses. This has helped to slowly build a slab on top of a generally weak foundation. Due to the gradual nature of these loading events, avalanche activity has been spotty in nature. Yesterday we received reports of two human triggered avalanches in mid elevation terrain (one report HERE). We have been experiencing collapsing for several days in a row at all elevations but not widespread avalanche activity. What this boils down to is that we are in the “gray zone” of MODERATE avalanche hazard. The snowpack structure is poor in most areas-there is a slab (up to 24”) sitting on weak snow near the ground. But there has not been quite enough of a load to create instability that is obvious and easy to predict.
Because of this, it is worth continuing to treat slopes above 35 degrees with suspicion. Cooler temperatures today will likely make the snow less reactive but the potential still exists for skiers or snowmachiners to trigger slabs up to 2 feet in depth. Exposing only one person at a time to steep terrain, spacing out across slopes and communicating your plan within your group will help to minimize your exposure to avalanche hazard.
Winds overnight kicked up into the 30-40mph range (with gusts to 61mph) out of the Northwest on Seattle Ridge. The winds at Sunburst have been significantly less (5mph average). Because of this, these slabs will be scattered about in pockets on primarily East facing terrain. Fresh new wind slabs will exist in pockets and will be most sensitive on steep slopes above treeline. Avoid snow in starting zones or above cross loaded gullies that have a smooth, rounded look to it. With this new load the potential also exists for smaller wind slabs to pull out deeper weak layers in the snowpack.
In the past 24 hours the mountains around Eastern Turnagain Arm have picked up a trace of new snow. Temperatures have been on the decline with daytime averages yesterday in the mid twenties F and current ridge top temps in the single digits to teens F. Winds at the Seattle Ridge Station over the past 12 hours have averaged 30mph out of the NW.
A small ridge of high pressure will build over the area today, bringing clear skies and cooler temps. Winds will blow out of the NW at 20-30mph and temperatures will climb back up into the teens to low twenties F.
The ridge over us today will be forced out by a complex low pressure system which will move into Southcentral Alaska tomorrow evening. We can expect snowfall to be light and temperatures to rise between Tues and Thursday of this week.
|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|
|04/05/21||Turnagain||Avalanche: Resort bowl Seattle creek head wall||Clint Kyffin|
|04/04/21||Turnagain||Observation: Center Ridge||Andy Moderow|
|04/03/21||Turnagain||Observation: Repeat Offender – Seattle Ridge||Troy Tempel|
|04/02/21||Turnagain||Observation: Seattle Ridge||Wagner / Schauer Forecaster|
|04/01/21||Turnagain||Observation: Pete’s||Schauer/ Cullen Forecaster|
|03/31/21||Turnagain||Observation: Tincan||Schauer/ Rothman Forecaster|
|Area||Status||Weather & Riding Conditions|