Jasper

Large natural avalanches are becoming more sporadic; however, human triggering remains likely and could result in significant consequences.
The Moderate rating below treeline reflects the overhead exposure to the persistent slab problem at TL and above.
Cautious route-finding,conservative decision-making essential.

Moderate

• We are uncertain about how quickly the snowpack will recover and gain strength.

Avalanche control on March 25 produced mostly no results, with only a few small storm slabs triggered by large explosives at treeline and below. Field teams observed a limited number of natural persistent slab avalanches that occurred post-storm at treeline on east to south aspects, running large and wide. Avalanche control on March 21 produced persistent slab avalanches up to size 4, coinciding with a widespread very large natural avalanche cycle.

The Icefield's alpine has received 70- 120 cm of new snow since March 15th. Maligne has received 30-50 cm. A late March temperature and rain crust has formed below treeline and exists up to 2100 m. A persistent weak layer of facets and temperature crust is buried 70-170 cm. The midpack is generally well consolidated with facets near the ground. Average snow depths for the Icefields are 150-220 cm, and Maligne is 80-140 cm. 

Thursday:

Cloudy with sunny periods and isolated flurries. Precipitation: Trace.

Alpine temperature: High -11 °C. Ridge wind west: 20 km/h gusting to 50 km/h. Freezing level at valley bottom.

Cloudy with sunny periods and isolated flurries. Precipitation: Trace.

Alpine temperature: Low -14 °C, High -8 °C. Ridge wind southwest: 15 km/h gusting to 40 km/h. Freezing level at valley bottom.

Mainly cloudy with scattered flurries. Accumulation: 4 cm. Alpine temperature: Low -10 °C, High -6 °C. Ridge wind southwest: 15 km/h gusting to 40 km/h. Freezing level: 1500 metres.

• Uncertainty is best managed through conservative terrain choices.
• If triggered, wind slabs may step down to deeper layers, causing larger avalanches.