Avalanche Forecast

Issued: Apr 10th, 2014 6:27PM

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

Tim Haggarty, Parks Canada

Waterton Lakes.

Even short periods of solar heating or rain may cause an increase in the hazard beyond posted Danger Ratings.

Summary

Weather Forecast

Flurries/showers can be expected Friday with Moderate to Strong West winds and freezing levels reaching 2100m. More Sustained flurries with light winds shifting to the N Saturday will only allow freezing levels to reach 1600m. With more sun expected Sunday freezing levels will return to 1900m although winds will stay unchanged.

Snowpack Summary

Strong solar heating has created moist snow on all but North aspects above treeline and solar inputs have allowed for only superficial freezing in the last few days at low elevations. Moderate to strong West winds continue to transport modest amounts of snow and have created thin and spotty slabs on E and N aspects TL and ALP.

Avalanche Summary

Daily loose moist activity on all aspects below treeline and to mountain tops on sun exposed aspects has been seen over the last few days. Minimal cooling overnight has kept solar slopes sensitive to daily solar inputs. This activity should diminish with the cooling expected Saturday however solar heating on Sunday will allow the pattern to resume

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Loose Wet

With poor freezes the last few nights and clear days, solar heating has allowed for widespread activity. Expect this activity to dissipate with cooling and clouds but to resume as the sun returns.

Travel early before the heat of the day, and avoid big slopes in the afternoon.Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Wind Slabs

West winds continue to transport snow at treeline and above on shaded aspects. Expect to find slabs to increase in their development as you ascend into the alpine

Be cautious as you transition into wind affected terrain.Be alert to conditions that change with elevation.

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Deep Persistent Slabs

The lower layers of the snowpack remain weak in many areas but are most likely to be triggered by a large load such as a cornice or smaller avalanche in thin areas at high elevations.

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

Aspects: North, North East, East, South East, South.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Apr 13th, 2014 4:00PM