Get an early start to the day before the afternoon heat arrives and destabilizes mountain slopes and natural avalanche activity increases.
This problem layer is the crust and facets created by early February's warm spell. It is down 30-90 cm in the snowpack and is a 1-10 cm thick crust or multiple crusts with a layer of weak facets above.
Strong and extended solar and temperature change is expected on all aspects. Open and exposed terrain will accelerate this process and may initiate deeper instabilities.
The base of the snowpack is inherently weak and untrustworthy. Tickling this deep layer would result in a high consequence avalanche. Any avalanche in the upper snowpack has the potential to step down to the base of the snowpack.
Sunday and Monday will be a mix of sun and cloud, 3 °C, light winds. Sunday will be 3300 metres freezing level and Monday will be 2300 metres.
Mountain Weather Forecast is available @ Avalanche Canada https://avalanche.ca/weather/forecast
Numerous loose wet avalanches occurred on many steep sunny aspects. Large slabs have been observed across Jasper running on the Feb Crust and some stepping down to ground. Saturday's explosive control work released a few size two slabs and wet loose avalanches.
The forecasted warmup will be a dramatic change to the surface and mid-pack condition of the snowpack. This change will happen over an extremely reactive crust interface down 35-60cm. This persistent weak layer has been consistently producing large natural avalanches. The equally worrisome basal depth hoar makes up the bottom third of the snowpack. HS ranges from 80 to 130cm.
