Fri, May 27, 2022 at 3:28pmIssued by: Ian Fowler
Sinking into wet snow past your ankles, rollerballs, and minor point release avalanches are all signs to avoid steep terrain. As the day heats up, snow will rapidly lose cohesion, and you will start to see wet avalanches. The danger will increase on all slopes. High northerly facing slopes will not be immune to warming. Cold snow remaining on these slopes could be particularly at risk of deeper slides where the snow may sheet off down to the frozen crust below. Start early and finish early.
Multiple days with no freeze in the forecast mean cornices will weaken, and these truck-sized blocks may collapse naturally or due to a person on them. Give the visible edge of the cornice a wide birth as they can break well back from an edge and don’t travel under them.
Saturday is another windy and warm day with temperatures near treeline reaching the mid to upper fifties. Clouds increase in the afternoon as our high pressure ridge breaks down. There is a slight chance of afternoon thunderstorms but most storms will be dry with just some gusty outflow winds.
The leading edge of a low-pressure trough moves over Colorado on Sunday resulting in extensive cloud cover, cooler temperatures, and continued windy conditions from the southwest. As the center of this system churns to our north, we will see periodic snow showers, mainly across the Northern Mountains. Snow will spread over more areas later on Sunday as cold front moves through. It looks like a good freeze is in store for Sunday night. The weather pattern is generally cool and unsettled through about Wednesday.
Snowpack and Avalanche Discussion
The Northern Mountains look like a frosted graduation cake due to storms depositing over 3 feet of heavy wet snow last week. Friday night's low temperature hovers in the mid to high-thirties, and Saturday highs climb to the mid 50s. Three nights with no freeze mean a less robust crust forms overnight, and the window for safe travel shortens. You should leave the trailhead early when the snow is solidly frozen. It might be time to dust off that headlamp, allowing safer and more efficient travel. Drop in on your line as just the surface inch or two is softening, and head back to the trailhead or lower angle terrain before you sink into the snow past your ankles. High elevation northerly facing slopes with cold snow may not have shed the snow from the week's storm. Elevate your suspicion of any steep slope that looks virgin and pillowy. Check how well the snow bonded to the underlying icy crust, and if you are sinking into wet snow even on shady slopes, it may be time to call it a day. Steep slopes with lots of rocks and thinner areas of the snowpack are places you are more likely to trigger avalanches. Wet avalanches are very heavy, and even small slides are difficult to escape. Consider the consequences of even a tiny avalanche if traveling in consequential terrain.
Cornices will increase as a concern over the coming days. Hot weather and the new load could help school bus-size cornices already sagging to reach a tipping point. If traveling along a ridge, stay well back from the obvious edge, and traveling under cornices is not recommended.
Cooler temperatures on Sunday result in a longer window of safer travel. You should continue to look for localized areas of wet snow where cool air did not mix with warmer pockets in gullies, hollows, and sheltered areas.