A Round-up Of 2014 Early Season Avalanche Conditions Nationwide

An early-season avalanche that ripped to the ground on a shallow snowpack in the Wasatch this November. Utah Avalanche Center photo.

From the first snowfall in the high country, what determines longterm snowpack stability often happens in the critical early parts of the ski season, and makes early snow storms, how they layer, and the weather in between important aspects of understanding potentially unsafe places and aspects to ski. Weak, upside-down snowpacks can cause problems all season long, and conversely, stable layers from the get-go can ease worries about deeply buried instabilities despite what may happen later in the winter.

Snow science is inexact, to say the least, which means that it is imperative that backcountry travelers understand the conditions and keep the forecasters’ expertise in mind, but remember that you and your friends are the ones who will be making the ultimate determination of what and when to ski. Using the ALPTRUTH system, which we covered in this December's Safety Week, is an excellent method to ensure you are all making sound decisions on what to ride and when.

We checked in on early season avalanche conditions at a few popular spots to give an overview of how the snowpack is starting out, along with website resources you should be familiar with if you plan to hit the road for some backcountry powder this season. The American Avalanche Association also runs a national resource website, avalanche.org, with a map and the websites of forecast centers on the homepage to make it easy to find information for most places you’ll be heading out to ski.

Mount Washington, New Hampshire

Tuckerman Ravine's Left Gully, and Headwall, slowly filling in on 12/19 but hampered by quite a bit of spacial variability. MWAC photo.

The Mount Washington Avalanche Center forecasters are reporting a variable snowpack with a lot of spatial variability–where the snowpack has different layers and depths in a seemingly small area, or differing results on similar slopes, aspects and elevations. In other words, watch out, and remember that results of that test indicating a stable snowpack might not mean anything 30 feet in another direction.

Expected warming temperatures will help the snow’s layers to bond, creating a more stable and solid snowpack as the winter gets underway, at least for the Mount Washington area. Terrain is a big factor in this area, and forecasters highlight the need to be aware of pockets of unstable snow and isolated terrain features. Mount Washington's infamous winds–which topped out at 98 mph in a storm last Thursday–add to the worries about spacial variability.

mountwashingtonavalanchecenter.org, (603) 466-2713

Colorado’s Rocky Mountains

As is usually the cause, persistent weak layers are again defining the Colorado snowpack. This persistent slab broke naturally near Mineral Basin the northern San Juans. CAIC photo.

Colorado is infamous for its persistently weak and twitchy snowpacks, and at this point the season is shaping up to be more of the same, according to Colorado Avalanche Information Center (CAIC) forecaster Ethan Davis. Three major storm events have created the snowpack, starting with a storm in late October which left a suspect ground layer near and above treeline on shady and north facing slopes, followed by an above average November as far as snowfall goes, with two storms.

Two weeks of mild, dry weather left a suncrust on southerly aspects, and surface hoar on northerly, shaded aspects–basically faceting the entire snowpack, warns Davis. Another 6 to 20 inches fell throughout the state in mid-December, loading this weak layer. These are the factors forecasters expect to keep the overall snowpack weak for some time, and the bottom line is pay close attention to CAIC bulletins around the state, and be aware that the snowpack has a typically weak structure with the potential to fail on one of several layers.

avalanche.state.co.us, 303-499-9650

Utah and the Wasatch

The aftermath of a skier-triggered avalanche on Catharine's Pass near Alta back in late November, which broke as a slab on weak facets in the snowpack. UAC photo. 

Utah’s Wasatch Range is renowned for heavy snowfall and relatively stable avalanche conditions, but not so far this season. Unusually dry conditions around Utah are especially notable in the Wasatch–a prime backcountry skiers’ destination. The last three winters have been well below average snowfall, the driest stretch since the late 1950’s. This season, another slow start to winter with low snowfall, has avalanche forecasters concerned again.

“We may be working towards a fourth winter of drought conditions, and thin snow means weak snow,” said Utah Avalanche Center forecaster Drew Hardesty. “That’s the case so far this winter.”

Storms that come in and deposit less snow, and with longer dry periods between them, promote the growth of facets and buried depth hoar. These are red flags for persistent buried weak layers once more snow begins to pile up as winter goes on.

utahavalanchecenter.org, 801-524-5304

Wyoming and the Tetons

Debris from a loose-snow avalanche in Death Canyon. A mid-December warm and dry period locked up the snow underneath, but a big storm now pounding the region will mean sluffs and storm slabs will be an issue for the near future. Peter Popinchalk photo via the BTAC.

After an unusually long, dry, and warm fall, winter got off to a late start in western Wyoming and the Teton Range. Beginning in mid-November, snow began to come in hot and heavy like a maritime snowpack, according to Bridger-Teton National Forest and Jackson Hole Ski Patrol forecaster Bob Comey. “We have a deep early season snowpack with a lot of strength right now,” said Comey. A mid-December period of warmth and rain up to 8,000 feet left a crust that has just been buried by the most recent storm, but forecasters don’t expect it to be a lasting issue. “There are isolated areas of concern still, but we are off to a great start,” says Comey.

Moving forward, periods of dryness coupled with other variations in the weather, such as high temperature gradients (warm days and cold clear nights, for example) causing facets, or rain or sun crusts, could cause issues higher up as the snowpack continues to deepen. Keep tabs on the avalanche bulletin and personal observations, but the good news is that the foundation of the snowpack in Western Wyoming is for the most part a solid structure, except for this week in particular, when a big warm, wind-loaded snowstorm fell upon much cooler and dryer snow that itself sits upon a firm crust layer. The resulting upside-down snowpack, for the moment, warrants caution.

jhavalanche.org, 307-733-2664

California And The Sierras

With Tahoe finally getting some decent snow, weather-associated wind slabs like this one on Mt. Judah last week are an issue, but overall persistent weak layers are mostly at bay for the area. Photo via the SAC.

The Lake Tahoe region started off with a series of warm snowstorms, and according to avalanche forecaster Andy Anderson, the general snowpack is not shaping up to have any persistent problems throughout the season. Major concerns at this point are going to be more associated with weather, such as storm slabs and wind slabs from redistribution of snow. An early season snowpack is still the state of affairs for the Sierras at this point, with the usual cautions for a still thin snowpack. Above 9,000 feet, there is a deeply buried weak layer, which would take a lot to trigger, but is still there, cautions Anderson.

Beyond that, terrain, recent weather patterns, and the avalanche bulletins should be what skiers focus on in the near future in this Sierra forecasting area.

sierraavalanchecenter.org (Lake Tahoe area)

esavalanche.org (eastern Sierra)

Montana

This snowpit dug in History Rock Meadows near Bozeman shows a relatively shallow snowpack and the ground-level facets that will be a lingering concern for some time to come. Photo via GNFAC.

One place that is not off to a particularly good start is the mountains around the snowmobile and skiing mecca of Cooke City, Montana. This area has been dealing with weakness at the ground level thanks to now-buried sugary facets that formed from early season snowfall. According to the forecasters, it is not green light conditions, and this lingering instability should keep backcountry travelers on their toes for the near future. Moving forward, although the weak layer may heal as new storms come in and compress the snow, it’s going to be a good idea to keep in mind there is a deep potential instability in the snowpack.

Slightly improved conditions exist in the more northern areas towards the Canadian border around Glacier National Park and Whitefish. The more reactive layers are a crust surface that formed during the last dry spell, but there is also a layer of facets at ground level to be aware of throughout the season, especially in any terrain or elevation with a thin snowpack. .

mtavalanche.com, 406-587-6981

flatheadavalanche.org, 406.257.8402

The Pacific Northwest

Steven's Pass (above), Mt. Baker, and others finally spun the lifts for limited terrain openings this past weekend. The area is victim to warm temps this early season that have produced more rain than anything white. Stevens Pass photo.

The PNW has been off to a very slow start, with an unconsolidated weak flow not throwing much moisture towards the Cascades. The one exception has been the northeast portion of the range–Washington Pass has been getting most of what moisture is coming through, but the rest of the mountains are sitting with only 15-20% of their normal snowfall to this point. 6 of the Northwest Avalanche Center’s 11 weather sites report record minimum snow for December 15th.

While some snow is on the way this weekend, more warm temps and rain are also expected according to Cliff Mass. By and large, at lower elevations it’s a simple wait for snow, while locations high in the alpine are going to be subject to storm and wind slabs as snow lands up high while rain continues down low.

nwac.us, 206-526-4666

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stash member Brigid Mander

All things skiing, fun lines, off the beaten path adventures, skid life, telling stories, and obscure vocabulary words. brigidmander.com