This is Ian Hoyer with pre-season avalanche, weather and event information for the Gallatin National Forest Avalanche Center on Sunday, October 23rd. This information is sponsored by The Friends of the Avalanche Center.
Well, that was a fast transition - welcome to winter! Rain switched to snow on Friday night and has piled up across the advisory area. Snowfall totals range from just a couple inches at lower elevations up to 1.5-2 ft at SNOTEL sites (7000-9000 ft) and likely even deeper at higher elevations. Snow water equivalent totals range from 1.7” in the Bridger Range and Cooke City up to 3.4” in Taylor Fork (see the Weather and Avalanche Log for specifics). Snowfall will continue today, favoring the Big Sky area with up to another foot falling by tomorrow morning. Temperatures will stay cool with chances for snowfall continuing through mid-week.
There is snow on the ground, so it’s time to think about avalanches. Avalanches this time of year are not uncommon, and have injured and killed people in past seasons (accident reports). It doesn’t matter if you’re looking to eke out some early season turns, chasing elk, breaking in those new snowshoes, or trying to squeeze in one last hike. If there are more than a few inches of snow - you need to be wary of steep slopes. You’re most likely to trigger an avalanche in places where wind has blown the new snow into deeper and stiffer drifts. But any slope with more than a foot of snow (even in patches) holds the potential for a dangerous avalanche.
The simplest way to stay safe is to avoid crossing or passing directly beneath any steep, snow covered slope. Even a small slide could push you into rocks or trees or pile up deep in a confined gully.
If you aren’t willing and able to identify and avoid all snow covered slopes steeper than 30*, you need to prepare for avalanches like you would mid-winter. That means having a partner, traveling one at a time in avalanche terrain, carrying rescue gear (avalanche beacon, shovel, and probe) and knowing how to use it. Also looks for cracking and collapsing of the snow as bulls-eye information that the snow is unstable, and clear signs to avoid steep slopes.
We are preparing for winter and beginning to collect snowpack information. We’ll be updating the Weather and Avalanche Log daily and issuing pre-season bulletins as needed throughout the fall. If you get out, please share avalanche, snowpack or weather observations via our website, email (firstname.lastname@example.org), phone (406-587-6984), or Instagram (#gnfacobs).
Island ParkWe are not issuing danger ratings.
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
This Wednesday, October 26, is the MSU Snow and Avalanche Workshop from 4:30-8:30 p.m. Dave Zinn and Ian Hoyer will be giving talks along with our Education Coordinator Shannon Regan. You can attend in person or virtually.
The Utah Avalanche Center Snow and Avalanche Workshop is a great opportunity available online from 6-9 PM on November 2 and 9.
If you’re headed out hunting in the coming days, read this new article Alex wrote on avalanche avoidance for hunters. If you’re thinking about skiing or riding, this accident report from October 2012 in the northern Bridger Range is full of good lessons for how things can go wrong when searching for early season turns.