I believe I heard the snowpack around here described as notoriously unstable and that it’s not a bad idea to just wait until spring.
Yeah, that's definitely true.
In very general terms, continental snow packs develop deep weak layers due to the following - relatively shallow snow pack, low density snow, longer breaks between significant snow storms and colder temperatures. In the San Juan's the air temps are generally well below freezing for most of the winter. The temperature at the ground is right around 32F. This means that there is a temperature gradient (TG) between the snow surface and ground running through the snow pack. Remember, the snow pack is relatively shallow. And there are big gaps between storms which means that the snow pack gets different layers of density snow at these storm interfaces. You've probably heard the term "high TG snowpack" or TG weakness. At these storm layers due to the high thermal gradient, hoar frost (weak snow crystals) grow usually right under the denser storm interfaces and sometimes right at the ground. You can see hoar frost grow right on the snow surface after a few cold clear nights with no wind too. Same TG crystals grow at low density transitions within the layers of snow too. This TG snow or hoar frost is the "weak layer" that skiers/snowboarders can trigger to slide causing soft and hard slab avalanches that we all fear.
My limited experience with touring and back country riding in the middle of winter near Crested Butte was scary AF. Especially coming from a PNW background. Relatively low angle moderate slopes with convex rollers were easy to trigger and sometimes down to deep month old layers! No Thanks!
You are right about spring. In continental snowpack as the days get longer and warmer the ground temp and surface temp are closer to 32F, thus less thermal gradient (TG) crystal formation going on at the ground and the different storm layers. And also, as the snowpack deepens and time goes on, those weaker layers get crushed (or healed) leading to better stability and safer traveling.
In contrast, marine snow packs are generally deeper and heavier. The temperature at the surface is closer to 32F so there is usually not a thermal gradient through the snowpack, thus no hoar frost (weak crystal) growth at interfaces within the snowpack. Also, the heavier snow and rain we sometimes get tends to crush/heal deeper unstable layers within the snowpack. Thus it is more rare for coastal areas to have long term avalanche concerns/hazards.
That is not to say, coastal mountains are not dangerous - they are! During and just after a big storm, it is common to get soft slab avalanches in the west. Many folks out here get fooled by past stable slopes and don't account for very recent snowloading or wind transport when seeking out powder. It is usually within 24 hours of a big snowfall that we get our skier triggered events.
Dang, that turned into a bit of TLDR, but hope a few of you may be interested....