Another sunny day is expected Friday, with freezing levels reaching 2800 m. Avalanche hazard will start as Low, but the alpine rating reflects the highest expected over the day —start and finish early.
Click the link for advice on dealing with spring conditions
As Friday and Saturday get progressively warmer, more incidents of cornice failures may occur. A large cornice failure may trigger the persistent layers in the slopes below. Consider and manage your exposure to terrain overhead.
An 80 cm thick midpack slab sits over a weaker, facetted base. On most slopes, recent sun crusts and a buried March 27 rain crust cap this slab, adding strength as long as it is frozen. We suspect it would take a large trigger, like a cornice or intense solar input, to trigger these deeper layers.
Monitor daytime temperatures and solar input, as the likelihood of avalanches will increase over the day. Start and finish your tour early to avoid this problem.
No avalanches besides minor wet loose slides out of steep solar terrain were observed Thursday, and no other avalanches in the past few days.
No avalanches reported on the persistent weak layer since the last warm-up on April 18th, when there were 2-3 size 2.5 avalanches off Pilot Mtn.
Hard surface crusts exist to ridgetops in the AM on solar aspects, and at treeline and below on northerly aspects. The top 10-20cm was moistening at the ski hills in the afternoon.
North alpine slopes hold 5 - 15 cm of dry snow over firm surfaces. The March 27 crust is 30-70 cm deep and extends to about 2500m on North slopes, reaching ridge top on solar aspects.
Below the settled mid-pack, weak facets and depth hoar remain.
Friday: There should be an overnight freeze to start the day, with freezing levels rising to 2800m in the PM, light winds, and plenty of solar input.
Saturday: There will likely be a weaker freeze in the morning, and freezing levels could possibly go above 3000m in the PM, with light winds and sun.
See table below for more details.
