South Columbia Avalanche Forecast

Feb 18th, 2020 5:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs.

Enjoy the sunny weather, but remain cautious around sun-exposed and wind affected slopes.

Summary

Confidence

High - The number, quality, or consistency of field observations is good, and supports our confidence.

Weather Forecast

TUESDAY NIGHT: Clear, light northwest wind, alpine temperatures drop to -15 C.

WEDNESDAY: Sunny, light wind, alpine high temperatures around -5 C.

THURSDAY: Sunny, light to moderate south wind, alpine high temperatures around -5 C.

FRIDAY: Sunny in the morning with increasing cloud in the afternoon, moderate southwest wind, alpine high temperatures around -5 C.

Avalanche Summary

Recent avalanche activity has been limited to small (size 1-1.5) slab and dry loose avalanches. Over the weekend there were numerous reports of 10-30 cm thick skier-triggered slabs on steep roll overs and wind loaded slopes. The majority of activity on Monday was on south and east facing terrain around treeline elevations. Looking forward, slab avalanches will remain possible to trigger, especially on sun-exposed and wind loaded slopes.

Snowpack Summary

Sunny weather could weaken cornices and the upper snowpack on steep south-facing slopes. 30-60 cm of recent storm snow is gradually settling and gaining strength, but has shown some isolated signs of reactivity on wind loaded slopes and steep convexities in sheltered terrain (where the snow sits above small surface hoar or sun crusts). These interfaces are unlikely to develop into a persistent problem, but for the next few days storm slabs could remain reactive on these isolated terrain features. The lower snowpack is generally well settled and strong.

Terrain and Travel

  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.
  • Be careful as you transition into wind affected terrain.

Problems

Storm Slabs

An icon showing Storm Slabs

Likelihood

Unlikely-Possible

Expected Size

1 - 2

Storm slab avalanches are possible to trigger on wind loaded or steep convex slopes, and may release naturally on sun-exposed slopes in the heat of the day.

Aspects:

All aspects.

Elevations:

All elevations.

Valid until: Feb 19th, 2020 5:00PM