We're not quite into a full on spring snowpack yet, but, it's not far off. The steady cycle of warm days & cool nights has a big effect on the snowpack, and a good rule of thumb is this: When the snowpack is firm & supportable in the mornings after a good overnight refreeze, things are good to go. But, as warm temperatures & sun begin to warm the pack, it begins to loosen up from the top down. If you get off your machine and suddenly find yourself sinking in to the once supportable 'pack, then it's time to call it a day.

My colleague Brett Kobernik produced this explanation earlier this week & I think it's worthwhile:

Often when we think things are going to come unglued it ends up being a non-event. The weather needs to be just right to produce a natural wet avalanche cycle. Some days when you expect wet activity, a few clouds roll through and keep temperatures just cool enough so it doesn’t happen. Other days when you think cloud cover will keep things cool enough, it “greenhouses” and produces a wet cycle. A slight breeze can be enough to keep things in check when you might think it’s going to let loose. But, will the warm temperatures override everything? To tell the truth, we just don’t know exactly how these warming events will unfold. The bottom line is that in the spring when the indicators are there, you need to behave as if wet activity WILL happen always thinking about avoiding the bottoms of avalanche paths and staying out of gullies. Plan your route so that if things start to get bad you have a safe exit.

Here it is, the last forecast of the year, and we're still talking about Deep Slabs. In steep rocky locations facing the north half of the compass, it's still entirely possible to trigger a deep, destructive & potentially un-survivable hard slab as evidenced by last weekend’s fatal accident. These low probability/high consequence events are notoriously difficult to forecast, but they are certainly avoidable by simply avoiding the big steep bowls. If you do decide to jump into one of these larger features, be aware that there is a chance of pulling out the big one. Furthermore, stay heads up to how warm the snowpack is getting. At some point the long warm days are going to re-activate the deep slab as melting water percolates though our snowpack and lubes up the deep buried weaknesses.

Cornices are massive at this point. Warm temperatures will weaken them and you can expect cornices to fail naturally throughout the spring. Give these monsters some space; you certainly don't want to be underneath one when it falls!