Avalanche Forecast Lizard Range and Flathead

Date Issued: Valid Until:

Avalanche Canada ghelgeson, Avalanche Canada

Avalanche Forecast

Fri Apr. 12th ยท 5:19PM

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low
Wind Slabs Wind Slabs

Alpine

Danger Ratings Considerable

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low
Watch for fresh slab formation late in the day in high elevation north facing features as a storm rolls into the region. If alpine storm totals exceed 20 cm, the danger will be considerable. This storm could offer a nice refresh for Sunday.

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Saturday

Weather Forecast

Little change is expected Saturday, but it looks like a frontal system should track into the region late Saturday into Saturday night. We're expecting it to be quite convective which makes it hard to pin down total snow amounts, but 10 to 20 cm by Sunday morning is within the realm of possibility. Stay tuned for more details.FRIDAY NIGHT: Freezing level around 1500 m, light to moderate west/southwest wind, trace of snow possible. SATURDAY: Scattered cloud cover in the morning building to overcast in the afternoon, freezing level around 1600 m, light southwest wind in the morning building to strong southwest wind in the afternoon, 5 to 10 cm of snow is possible in the afternoon. Another 5 to 10 cm is expected Saturday night.SUNDAY: Broken cloud cover, freezing level around 1600 m, moderate to strong west/southwest wind, trace of snow possible. MONDAY: Scattered cloud cover, freezing level rising to around 1700 m, light variable wind, trace of snow possible.

Avalanche Summary

On Thursday, explosive control was able to initiate a few loose dry avalanches up to size 1.5 which failed in the recent storm snow. In the afternoon skier controlled loose wet avalanches were easily triggered at treeline and below up to size 1.5 on sunny aspects. No natural avalanche activity was reported and no new avalanches were noted in alpine elevations. Its important to make observations with changing conditions through the day and know when to pull back or dive into your line. If you're unsure, its best to have a conservative approach.

Snowpack Summary

15 cm Thursday night brings 20-35 cm of recent accumulated snow since last weekend which sits above a supportive crust at treeline and in the alpine. 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 isolated reactive wind slabs may exist and 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. Below treeline the snowpack is becoming isothermal.

Problems

Wind Slabs

Wind Slabs

Wind slabs on high elevation North facing slopes may still be reactive to human triggers. Shallow fresh wind slabs may begin to form late in the day as new snow and strong southwest wind come together.

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

Aspects: North, North East, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2