Avalanche Canada:ย Early Season Snow Conditions |ย By:ย James Floyer
If thereโs enough snow to ride, thereโs enough snow to slide.
Snow has started to accumulate in many mountain areas this season. There have already been reports of avalanches, including one significant near miss.
Winter-like wind and storm slabs form readily in alpine bowls and around ridgelines and are often poorly bonded to the layers below. Itโs worth remembering that on smooth terrain (like glaciers, summer snow, grass, shale slopes and rock slabs) as little as 30 cm of snow is enough to create avalanches.
Just as in the middle of winter, avalanche danger will go up during and immediately after a snow storm. If the temperature rises during or after a storm, or if there is rain, avalanche danger is likely to increase further.ย
In some areas, early season weak layers may form. The most common scenario is a layer of sugary snow (facets) that can grow near the ground when temperatures get cold and there isnโt much snow cover. Sugary facets may also be found on glaciers at the bottom of this seasonโs snowfall. That’s what happened in the picture below, which was sent to us from an area in the Purcells.
If youโre heading out before avalanche forecasts are available, gather as much information as possible about local conditions before you travel:
- Talk to people who have been out recently. Preferably talk to experienced local riders who have been near to or where youโre going in the past couple of days. Did they see any avalanche activity? Did the snow surface feel dense? Were cracks shooting out from their skis? Did it have a loose, weak layer near the ground?
- Keep track of the weather. Danger is often highest during and immediately after a storm. Give the snowpack time to settle and stick to mellower terrain if the weather has recently been stormy.
- Know whatโs under the snow youโre riding on. Riding on steep terrain where a fresh slab overlies last yearโs old snow or glacial ice carries additional risk.
- Ice climbers are traditionally at greater risk in early season. Many ice climbs form beneath high elevation start zones that arenโt visible when youโre actually on the climb. Know the terrain and assess snow conditions that lie above your route. Seek knowledge and advice if you are not familiar with a climb and canโt see whatโs above. Be cautious on the approach as well as on your climb. Choose safe belays spots and carry transceivers, probes, and shovels.
Early season avalanches at any elevation have the potential to be particularly nasty as rocks, slash, deadfall, stumps, etc. are exposed or just below the surface.ย Even a small avalanche that pulls you over and/or through an obstacle course like this can be deadly serious.
This is a great time to check and maintain your safety equipmentโput fresh batteries in your transceiver, repair or replace damaged shovels and probes, test your balloon pack. Then refresh your rescue skills with some early-season practice in non-avalanche terrain. Make sure everyone in your group knows how to use their safety gear and consider taking a Companion Rescue course to refresh your skills. .
Finally, if you do head out, please tell us and others what you see by submitting to the Mountain Information Network.
Have run and ride safe!
James Floyer