Avalanche Forecast

Issued: Apr 10th, 2019 4:19PM

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

swerner, Avalanche Canada

South Rockies.

Isolated pockets of reactive wind slab may be found at upper elevations on Northerly aspects. The sun packs a punch this time of year and even small doses can initiate loose wet avalanches.

Summary

Confidence

Low - Due to the number of field observations

Weather Forecast

Unsettled weather leading into the weekend with a mix of sun and cloud and some convective precipitation. TONIGHT: Possible trace of new snow. Alpine temperatures -6 and freezing levels 1400 m. Ridgetop winds moderate from the southwest.THURSDAY: A mix of sun and cloud with alpine temperatures near -2 degrees and freezing levels 2000 m. Ridgetop winds light from the southwest.FRIDAY: Cloudy with snow amounts 5-10 cm. Alpine temperatures near -3 and freezing levels 1700 m. Ridgetop winds moderate primarily from the southwest.SATURDAY: Cloudy with a trace of snow. Alpine temperatures near -2 and freezing levels 1800 m. Ridgetop winds will generally be light with strong gusts from the southwest.

Avalanche Summary

No new avalanche activity reported from this region on Wednesday, the following is all from the Lizard Range and Flathead region: On Wednesday, numerous natural loose wet avalanches up to size 1Â occurred mostly from steep alpine terrain.

Snowpack Summary

10-15 cm of accumulated snow from the past few days is moist and has turned to shmoo from daily warming at treeline and below. A supportive crust sits below the recent snow above 1400 m. Below 1400 m the snowpack is becoming isothermal. During the heat of the day, especially under direct sun, the snow surface becomes moist or wet almost everywhere. The exception being high elevation north facing features. Steep, north facing, alpine terrain may still hold a cold, dry, snowpack where a well settled slab rests on weak facets (sugary snow). Although unlikely, human triggering of persistent slabs on this layer may still be possible, especially in rocky alpine terrain with a shallow or highly variable depth snowpack.

Problems

Wind Slabs

Wind slabs may be reactive to human triggering especially on North facing slopes in the alpine.

Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.

Aspects: North, North East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Loose Wet

The likelihood of loose avalanches increases as temperatures warm through the day and/or if the sun comes out for a period of time. Loose wet avalanches are more likely in areas with fresh snow.

A moist/wet snow surface, pinwheeling and natural avalanches all indicate a weakening snowpack.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Valid until: Apr 11th, 2019 2:00PM