Significant snowfall, periodically accompanied by wind has added stress to underlying persistent weak layers and the avalanche danger is CONSIDERABLE on all steep, mid and upper elevation slopes that face W-N-E. Human triggered avalanches are likely in these areas and these slopes should be avoided for the foreseeable future. In addition, there is a MODERATE danger for human triggered avalanches involving new snow on all aspects.A ride in an avalanche with the current low snow conditions will be rugged. Temper your enthusiasm for the new snow, and keep your slope angles low.
Moderate to strong SE winds overnight have blown and drifted snow at upper elevations. Unstable wind drifts will most likely be found on slopes facing W-N-E. Fresh drifts will add additional weight to to buried persistent weak layers in these areas, and human triggered avalanches 2'-3' deep are likely.
Human triggered, loose snow sluffs, or soft slab avalanches within the most recent snow remain possible on steep slopes on all aspects today. I did not find the new snow to be particularly sensitive yesterday, but it wasn't bonding well in snowpits. Any new snow avalanche triggered on a slope with a buried persistent weak layer will almost certainly cause a a deeper and much more dangerous avalanche.
It's no secret by now that persistent weak layers of weak, sugary, faceted snow are rife on all north-facing aspects. These have been producing signs of instability such as collapsing and cracking since our first major snow load back in December, and they resulted in natural avalanches in this most recent storm cycle. Unfortunately, weak layers are beginning to present themselves, along with signs of instability on other aspects including W and SW in areas that hadn't been wind-blasted, or that are sheltered by trees. I can only assume they are appearing on SE aspects as well.
Check out the most recent blog post from Chris Benson with a recap of the current state of the snowpack and an analysis of the sometimes thin line between Moderate and Considerable danger.
The Geyser Pass Road will be closed for plowing this morning.
Cross Country Ski Trails were packed out by The Lower Utah Nordic Alliance (LUNA) yesterday. You can follow them on Instagram @luna_moab.
I observed several natural avalanches in Gold Basin yesterday that likely ran during the storm Sunday night. These all occurred in very steep, radical, N-NE facing terrain and some were repeat runners from the Dec 28 cycle. Tim Mathews detailed this slide in Exxon's Folly, and I've reported on several slides that occurred on the Snaggletooth Ridge.
Exxon's Folly avalanche observed on Jan 25. Photo by Tim Mathews.
24 Hour Snow 2" 72 Hour Snow 11" Base Depth in Gold Basin 37" Wind SE 15 G25 Temp 4F
We picked up another inch or two of snow since yesterday morning bringing totals since Friday up to 17". SE winds ramped up overnight blowing in the 20-30 mph range with gusts into the 40's for a few hours. They started backing off around 2:00 a.m. Today will be mostly cloudy with moderate, ridgetop SW winds, and high temps in the mid-teens. Skies should clear overnight. By Wednesday, a strong atmospheric river event will slam into the Sierra Mountains. SW flow aloft ahead of a trough stalled off the Pacific Coast will feed moisture in the form of clouds into southern Utah while allowing for chances of snow through the remainder of the week to points north. By Friday, the trough will move across the Great Basin although with energy much diminished. We'll see a chance for snow Fri-Sat.
Wind, temperature, humidity on Pre Laurel Peak (11,700')
Snotel site near Geyser Pass Trailhead (9600')
Storm totals at the Gold Basin study plot (10,000')
Snowpack Discussion
Snow is piling up and adding additional stress to our weak and faceted snowpack and it isn't rocket science to know that this has produced dangerous avalanche conditions. Deep wind drifts have also formed at upper elevations. In my travels yesterday I continued to observe signs of instability such as cracking and collapsing in the snowpack, even on slopes with a southerly component. Tim Mathews was up as well and reported more of the same. He also included a great video on current avalanche conditions. Read his observation here. In addition to dangerous avalanche conditions, we also continue to have low coverage, so add that to your list of hazards and be safe out there.
This forecast is from the U.S. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.
