Early Seasons Avalanche Conditions exist. Lower elevations are clear of snow but higher elevations have enough snow to have avalanche problems. Ice climbers should pay close attention to overhead terrain at this time.
Weather Forecast
New snow is slowly accumulating in Alpine areas. Keep an eye on freezing levels and input from new snow and winds and temp. Ice climbers who are travelling in gullied terrain accessing early season ice routes should be travelling with avalanche gear where appropriate and think about overhead terrain. Our observations are very limited at this time of year so this is more of a "heads up" to get people to start thinking about avalanche season.
Avalanche Summary
Small thin slabs have been observed in steep alpine terrain along ridgelines. Some loose slides have also been observed as temperatures warmed up. Ice climbers should be thinking about avalanches right now despite many of the approaches being snow free. Overall observations are very limited at this time of year.
Snowpack Summary
First of all, observations are VERY limited. Snow is beginning to accumulate in Alpine areas despite many lower elevations areas being snow free. Reports from last week in the Aster Lake area was up to 60cm of snow in Alpine terrain with pockets of snow along ridgelines and other areas up to 1m deep. Our weather stations are just coming online for the winter here and we are just updating and maintaining them so some of the readings regarding snow depths may be slightly off. As of 4pm on October 20th, the alpine looked to be a pretty snowy place.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.