Avalanche Forecast

Issued: May 3rd, 2013 4:03PM

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

Mike Eder, Parks Canada

Jasper.

Clear skies and intense solar radiation will increase the avalanche danger quickly and dramatically later in the day. Avalanches may occur that run full path down into the trees. Start and finish your trip early.

Summary

Weather Forecast

Saturday may see some broken clouds as the skies continue to clear. Sunday and Monday will be sunny with daytime temperatures approaching the low 20s in the valley bottom with freezing levels close to 3000m. By midweek, the forecast returns to mixed sun and cloud with the occasional bit of precipitation thrown in.

Snowpack Summary

The 40cm of snow that fell last week in the Icefields area has been blown into windslabs below easterly alpine ridgelines. On Southerly aspects, this new snow is becoming wet and is sliding on the buried suncrust. Relatively warm overnight temperatures are limiting the development of a supportive crust.

Avalanche Summary

On Thursday, several loose wet avalanches were reported in the Icefields Area on South facing alpine slopes. These avalanches involved last week's storm snow and are running far (300 to 400 m). No new avalanches were reported on Friday.

Confidence

Timing or intensity of solar radiation is uncertain on Saturday

Problems

Loose Wet

Warm temperatures and strong solar effect are creating loose wet avalanches with last weekend's storm snow that are picking up mass and traveling far.

Start and finish early before the surface crusts melt.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 - 3

Wind Slabs

40cm of storm snow has fallen since Saturday. West and NW winds have moved this snow onto lee aspects. South facing aspects are particularly likely trigger areas where the bonding of the new snow to the old melt freeze crust is weakest.

Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Cornices

Large cornices are looming. On failure, deep releases may run far into the valley bottom.

Extra caution needed around cornices with current conditions.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: May 4th, 2013 4:00PM