Avalanche Forecast

Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system.

TUESDAY NIGHT: Cloudy and unsettled with flurries, 10-20 cm overnight. Moderate southwest wind, alpine low -10C, and freezing level hovering around 1000m.

WEDNESDAY: Snow, 5-15 cm falling through the day, accumulating 20-35 by the end of the day. Moderate southwest wind decreasing though the day, alpine high -2C, and rising above 1500 m by days end.

THURSDAY: Unsettled with flurries and sunny breaks, 5 cm. Light west wind, alpine high +1C, and freezing level rising to 1500 m.

FRIDAY: Unsettled with isolated flurries, trace to 5 cm. Moderate west wind, alpine high -1C, and freezing level beginning near valley bottom rising to 1600 m.

On Monday, explosives triggered several size 1-1.5 avalanches on NW-N-NE aspects above 1800 m. Small dry-loose avalanches were reactive to skiers in steep terrain. And several natural storm slab avalanches size 2-2.5 were reported in Glacier NP, occurring on north-northwesterly aspects above 1950m.

On Sunday, explosives and skier traffic triggered numerous size 1 avalanches. A few small dry loose avalanches and sluffing in steep terrain was also reported.

On Saturday in Glacier NP, a handful of storm slabs size 1.5-2.5 released naturally from steep north-northwest aspects above 2000 m. A large (size 2.5) glide crack release from a west aspect.

On Friday, several glide slab avalanches (size 2-3) were observed on south and east aspects around the TCH highway corridor. Loose wet avalanches to size 2.5 were reported around the region; a natural loose-wet cycle was reported around Rogers Pass initiating with evening rainfall.

Southwesterly winds and flurries will form fresh slabs in lee features. 20-35 cm (up to 60 cm in areas) recent snow covers dry and compacted snow on polar surfaces above 1800 m and crusts on solar slopes; storm snow has been sluffing easily on the crust. In some areas of the region, surface hoar (4-10 mm) has been reported below the recent storm snow in shaded north-facing slopes at upper treeline and above. Large cornices loom over alpine ridgetops. Spring temperatures and sun are producing a melt-freeze snowpack below 1600 m and higher on solar slopes.

Persistent weak layers of surface hoar, crusts, and/or facets 80-120 cm down have been unreactive and no recent avalanches have been reported on these layers.

• Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
• Dial back your terrain choices if you are seeing more than 25cm of new snow.
• Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
• Pay attention to cornices and give them a wide berth when traveling on or below ridges.
• Back off slopes as the surface becomes moist or wet with rising temperatures.
• Remain vigilant for changing conditions.