Avalanche Forecast

Issued: Apr 23rd, 2014 5:51PM

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

jon stuart-smith, Parks Canada

Waterton Lakes.

Watch for precip, 10cm at higher elevations, but rain at lower elevations, especially Sat. Remember, even small amounts of solar heating or rain can weaken snow quickly to cause an increase in the avalanche hazard beyond the posted danger ratings.

Summary

Weather Forecast

Scattered flurries on Thursday but freezing level still up to 2000m. Accumulation might but up to 5cm. Friday the sun might pop out for periods with freezing levels climbing to 2300m. Saturday another system will move over the area with snowfall of up to 10cm. Freezing level will still be around 2400m however.

Snowpack Summary

No snowfall over the last few days and warm temps with cold nights has created a new crust to ridgetop on all solar aspects and high up on N aspects as well. The deeply buried February Facets and early season Basal Facets remain weak and will likely wake up with significant and sustained heating.

Avalanche Summary

A few isolated loose moist avalanches on all aspects and elevations with daytime heating.

Confidence

Due to the number of field observations

Problems

Loose Wet

Even short bursts of solar heating can rapidly affect the snow this time of the year. With mild temperatures in the forecast, watch for rain to affect the snow at lower elevations.

Travel early on frozen crusts before the heat of the day.Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Deep Persistent Slabs

Solar heating has weakened the upper snowpack treeline and below. With continued warming, a skier traveling through a thin spot or a large load hitting a slope such as a cornice fall or smaller avalanche could potentially trigger these serious slabs.

Pay attention to overhead hazards like cornices.Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Apr 26th, 2014 4:00PM