Talk about full on winter! It’s really hard to believe it’s almost May with the full on conditions today. No visibility, temperatures in the teens, and 8.3” of snow in the past 48hours as made for more like a February afternoon than a typical spring day. We are most concerned about the increasing avalanche danger that has developed over the past 24 hours with some areas currently bumping the upper end of the Considerable rating.
Fine grains are mixing in with average sized crystals which are producing a high water content per inch of snowfall packing into some fairly dense slabs. As we expected the main weaknesses can be found above the old surface in lower density slabs created yesterday during periods of light wind. Snow should taper overnight, but forecasts expect continued low visibility and temperatures in the high teens, perhaps reaching 20F on the summits. A blustery morning should give way to a diminishing wind in the afternoon, but currently it appears a chance of precipitation will keep all of us on our toes for the day.
With the information I’m seeing right now, along the weather that was slapping my face today, there is no way to sugarcoat or get around the reality that we will have avalanche issues tomorrow. Expect to see an elevated avalanche danger rating for a number of areas with some “Considerable” slats probable. Avalanche experience, skills, equipment and a history of good conservative decision making will be important. If you have these skills and abilities several other issues and challenges would run through my mind. 1. With potential low visibility, and being a Saturday in April, I would have a fair amount of angst for triggers above me that I can’t see. Expect some users coming in from multiple locations like hyenas converging on desired prey 2. Will someone adjacent to you, seemingly far away, trigger an avalanche that will propagate to your location. Or 3. To ski something safely will ‘ski cutting’ a slope to clear it send snow down onto others below. Frankly, slab instability and lots of people just don’t mix in the confines of an alpine cirque with avalanche paths that converge in multiple locations. It is very difficult to mitigate the multiple hazards that are reasonable during a quiet day midweek versus dealing with a busy Saturday. It can spell a disaster mixing hazards and crowds. I don’t say these things lightly, but I think it’s important to accurately portray the potential situation tomorrow. And although it’s not lining up as the cover shot of the “Worst Case Scenario” books it might be found on page 5 or 6.
Okay that was important to get across. Now how could it be not all that bad? Loading and snowfall today has me believing that we are fully in the midst of Considerable avalanche danger. This means that natural avalanches are possible. If this occurs in numerous slide paths today/tonight we may rid ourselves of a good deal of hazard. Although this is hard to plan or count on, it’s a possibility. If snow shuts down overnight the concern for natural avalanches will dissipate a bit tomorrow which may leave us with a number of areas potentially being Moderate on Saturday. This is quite plausible, but we will undoubtedly have concern for human triggered avalanches. “Moderate” means a lot of different things to people. Read the full meanings, size, and potential destructive forces for “Low”, “Moderate”, and “Considerable” in the scale below. For a minute, focus only on the definitions for LOW and CONSIDERABLE. There’s a pretty big gap between them isn’t there!!?? Well that’s the hole MODERATE is trying to fill. So in reality there is a difference between instability that is just a bit above Low versus just below Considerable. I think tomorrow’s Moderate will be just coming off of Considerable.
I recognize these are hard things to plan around for coming to the mountain or not, but for what I’m seeing it may not be the best Saturday to head for east facing higher terrain from the Gulf of Slides to the Northern Presidentials. Some improvement for Sunday is likely, but anticipate some lingering avalanche instabilities. Truthful and accurate reporting is important to us and I frequently ask myself the self-monitoring question “Am I crying wolf?”. Although I do believe things can play out a number of ways overnight the above discussion reflects a high likelihood of how it will all play out tomorrow. Be sure to check the Avalanche Advisory each morning before heading up into avalanche terrain. See Jeff’s video post about descending from the Ravine. We’ll see you in the hills or on the internet. Chris