Mt Hood

Look for wet-snow instabilities to increase as the day warms, especially on middle- and lower-elevation slopes that may see a lighter refreeze. Track the surface softening as the morning heats up and consider moving to a shadier aspect if you’re sinking past your boots in wet, mushy snow. Keep other spring mountain hazards in mind, such as firm morning travel, rock/ice fall, or sporadic cornice failures that may unglue with daytime warming.

Tuesday brought high winds that helped surfaces refreeze, especially at more wind-exposed elevations, despite elevated freezing levels in the 10,000-foot range. Tuesday night should offer similar conditions with a few high clouds and strong enough winds for surfaces to lock up. This pattern is helping the snowpack enter a spring diurnal cycle with daily freeze and thaw. Lower and middle elevations, however, may not see the most confident, inspiring reset, which may lead to wet-snow instabilities popping up earlier in the day. 

This time of year is all about timing. As the day heats up, expect increased chances of triggering small, wet avalanches where the snowpack feels wet and sloppy. Typically, the threat of these avalanches will follow the sun around the compass begining on east-facing slopes during the morning and moving to west aspects in the afternoon hours. As the day warms, monitor surface conditions and boot penetration. If you’re sinking past boot top in wet, heavy snow or encountering sticky surfaces, move to shadier aspects. Starting your day early is a great way to help you reduce your chances of being out when the mountain starts shedding. Prolonged warming has also weakened cornices and widened glide cracks. Limit exposure beneath overhanging snow features, as they can fail without warning.

Since April 3rd, freezing levels have been flirting with the summit of Mt. Hood at nearly 10-11,000 ft. The first warm days came as a shock to the dry, upper snowpack, with easily triggered wet loose and even a couple of naturals reported. As high freezing levels persisted, natural wet loose mainly ran their course, while human-triggered wet loose could still be pushed in very steep terrain. On Monday, the Mt. Hood Climbing Rangers reported deeper water percolation and more stubborn wet loose than on previous days. They also found a supportable crust capping dry snow at higher elevations that broke down with daytime warming (observation here).

It's that time of year when you should keep other mountain hazards on your radar. Expect mornings to be firm with long, sliding falls being your primary concern. Pack the appropriate traction and self-arrest tools for your objective. Also, consider rock or icefall as the day heats up. The Mt. Hood Climbing Ranger page is a great resource for upper mountain planning. 

Are you heading out?  Let us know what you see by submitting an observation here or on the AvyApp.