Danger ratings assume a mostly cloudy day. If the sun is strong for more than a couple of hours, increase avalanche danger to CONSIDERABLE.
Confidence
Moderate - Timing or intensity of solar radiation is uncertain
Weather Forecast
WEDNESADY NIGHT: Flurries with possible accumulations from trace to 5 cm in localized areas. Alpine temperature low -10C. Light northwest winds. THURSDAY: Cloudy with sunny periods. Alpine temperature high -8C. Moderate westerly winds at ridgetops.FRIDAY: Mainly cloudy. Alpine temperature reaching -4C. Light southwest winds.SATURDAY: Cloudy with sunny periods. Dry. Alpine temperature reaching -2C. Light to moderate west winds. Freezing level between 1500m and 1800m.
Avalanche Summary
Several small (up to size 1.5) storm slabs avalanches (natural and skier triggers) were reported Tuesday in the Lizard Range. With this recent round of precipitations, storm slabs are likely to be remain reactive on exposed terrain at treeline and alpine.
Snowpack Summary
25-30 cm of storm snow now sits over various surfaces such as old and firm wind slabs in the alpine and open areas at treeline on all aspects. A widespread sun / temperature crust is also found hidden under this new snow on south facing slopes. Isolated pockets of surface hoar crystals have also been observed at the surface on north-facing slopes around 2000m right before this storm rolled in. The mid-snowpack consists of sugary faceted grains (facets) of different hardness. Two older layers of surface hoar still exist down 55-80 and down 95-150 around 1600-1900m .The lower snowpack is generally well-settled.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.