Avalanche Forecast

Issued: Apr 9th, 2019 4:21PM

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

swerner, Avalanche Canada

Lizard-Flathead.

An unsettled weather pattern exists through the forecast period. Expect new snow (if any) to form isolated storm slabs in the alpine and loose wet avalanches at lower elevations with daytime warming and periods of sunshine.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Wednesday

Weather Forecast

The region will see a fairly unsettled weather pattern through the forecast period. Convective spring-like conditions could bring pulses of new snow in some areas or none in others. TUESDAY NIGHT: Light snow amounts 3-10 cm at upper elevations and freezing levels 1300 m. Ridgetop winds light from the NE.WEDNESDAY: Cloudy with some sunny periods and light snow 3-8 cm. Alpine temperatures near 3 degrees and freezing levels 1900 m. Ridgetop winds 10-30 km/h from the southwest.THURSDAY: Cloudy with some sunny periods and a trace of snow. Alpine temperatures near 0 degrees and freezing levels 1300 m. Ridgetop winds light from the southwest.FRIDAY: A mix of sun and cloud. Alpine temperatures near 3 degrees and freezing levels rising to 2100 m. Ridgetop winds light with strong SW gusts.

Avalanche Summary

On Tuesday no new avalanches were reported. On Monday there was a natural loose wet avalanche cycle to size 1.5 on solar aspects as the new snow ran on the crust. Snowfall amounts are uncertain for the next 24 hours. Storm slabs may only be an avalanche problem with new snow and loading.With spring conditions, the avalanche hazard will fluctuate greatly depending on the strength of the overnight re-freeze and how quickly the snowpack is warmed up.

Snowpack Summary

Sunday night the region picked up 10 cm of moist snow which has turned to shmoo from daily warming. This snow rests on a supportive crust above about 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

Loose Wet

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

Loose avalanches may start small but they can grow and push you into dangerous terrain traps.A moist/wet snow surface, pinwheeling and natural avalanches all indicate a weakening snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Storm Slabs

Watch for isolated storm slabs to form in alpine terrain if the region receives more than 10 cm Tuesday night. Northerly aspects may hold the new snow longer as the southerly will become moist or wet during the day on Wednesday.

Be alert to conditions that change throughout the day.Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Apr 10th, 2019 2:00PM