Avalanche Forecast
Issued: Mar 2nd, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Loose Wet and Persistent Slabs.
jcoulter,
Avalanche Canada
Stability is gradually improving but there is uncertainty about freezing levels and snowfall amounts with convective showers tomorrow.
Test the bond of new snow on smaller features with low consequences before committing to bigger lines.
Summary
Confidence
Weather Forecast
Unstable airmass is causing uncertainty with the timing and intensity of convective showers into Friday.
Wednesday night: Light flurries possible 5-10 cm, light southerly wind, freezing levels should drop to valley bottom, treeline lows just below zero.
Thursday: Overcast with flurries 5-15 cm, light southwest wind (could get gusty at times), freezing levels 1300-1500 m, treeline highs around -1.
Friday: Light flurries 5-10 cm should ease overnight, mostly sunny day, freezing levels will be at valley bottom at night and rise to 1300 m during the day treeline highs of -2.
Saturday: Mostly sunny, light northerly winds, treeline highs of -2.
Avalanche Summary
On Wednesday morning storm slabs were still reactive to explosives and ski cuts in the size 1-2 range. A widespread storm slab avalanche cycle with size 2-3 avalanches on a variety of aspects and elevations was reported from the region on Tuesday. Check out this recent MIN report taken from within the ski area boundary looking out of bounds towards the Mammoth Droppings.
Snowpack Summary
The Lizard Range has received over 90 mm of water from this system which has translated to about 40-60 cm of heavy, upside down type snow at treeline elevation. Convective snow/rain showers could add 10-20 cm to the snowpack on Thursday. Snow has generally been rain-soaked below 1600 m. All of this new load sits on a variety of old surfaces like sun crusts, freezing rain crusts, old wind-pressed snow or cold, weak snow crystals on shaded aspects. Moderate to strong southwest winds have likely contributed to cornice growth as well.
Storm slabs or loose wet avalanches may step down to old persistent layers such as the surface hoar layer buried at the end of January. The distribution of this layer is spotty in nature but has produced avalanches and snowpack test results in the past week, mostly in the Flathead. While it does not appear to be as widespread or reactive in the Lizard Range, it has been found in some locations.
The lower snowpack is well consolidated, with a crust/facet layer from early-December found near the bottom of the snowpack. It is currently considered dormant but with big rain on snow events, operators will be on guard. Check out the forecaster blog for more information.
Terrain and Travel
- If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
- Use small low consequence slopes to test the bond of the new snow.
- Be alert to conditions that change with elevation.
- Extra caution is needed around cornices under the current conditions.
Problems
Storm Slabs
Though stability is improving, human triggering of storm slabs should remain on your radar.
Test the bond of new snow on smaller terrain features with low consequences as you travel through various elevation bands and aspects.
Cornices have grown during the last system as well so give them a wide berth.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Depending on freezing levels overnight and Thursday, loose wet avalanches may be a concern at lower elevations where rain has destabilized the snowpack causing it to lose cohesion. These avalanches can start from a point and pick up a surprising amount of mass, especially in steep terrain and gully-type features. Storm slabs may entrain wet loose snow at lower elevations and run further than expected.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Persistent Slabs
Storm avalanches have the potential to step down to this deeper persistent layer in sheltered north-facing treed terrain.
Persistent slab avalanches are still possible due to a layer of buried surface hoar that is likely down around 50-100 cm. This problem is tricky to pin down because of its spotty distribution (it isn't a problem everywhere). It has been most reactive recently in the Flathead with reports of rider triggering, whumpfing and cracking a week ago.
Aspects: North, North East, East, South East, North West.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Mar 3rd, 2022 4:00PM
