Friday 3/20/20 - Thursday 3/26/20
This week on As the World Terns:
Green has been the theme in the first week of spring. This combined with sunshine (and folks realizing how weird it is to be quarantined with their families) spurred some impressive backcountry usage over the weekend. Observers noted melt-freeze crust and wind-hardened surfaces topping the snowpack in exposed areas. Near surface facets and even some isolated patches of surface hoar were found on sheltered slopes. A burst of snow Saturday evening refreshed the snow surface with 2-3 inches of fresh and caused some shallow loose wet and wind slab instabilities. On protected slopes, sluffs ran further and wider than is typical for this amount of snow due to the entrainment of near surface facets. Solar aspects produced some D1-D1.5 loose wet activity. Clouds returned Monday and winds increased from the Southwest. Snow returned Tuesday with Flattop Snotel recording as much as 0.9 inches of SWE. The new snow resupplied exhausted alpine fetches, allowing cornice and wind slab to grow on lee aspects. Winds remained consistent with spotty precipitation through the week. Observers found increasingly ticklish cornice up high and diurnal rollerball activity at low elevations. Please take some time to familiarize yourself with the recent Shelter-in-Place directive from the governor’s office as there is specific language pertaining to backcountry skiing. While this is by no means a backcountry ban, it is a reminder to dial back our risk tolerance even when the greenlight is calling. Don’t get complacent and stay safe!
Forecast Hotline: 406.257.8402
Call or text an observation: 406.66AVYOB