Above 2,500ft High
1,500 to 2,500ft Considerable
Below 1,500ft Moderate
Degrees of Avalanche Danger ?
Avalanche Problem #1: Storm Snow
Given the moderate-strong south winds expected during the storm, fresh storm slabs are likely to build up Tuesday-Wednesday, especially on north-ish aspects. These fresh slabs will be tender and easy to trigger on the dry, weak snow below. Wind loaded areas 28 degrees and steeper should be avoided. Below treeline, watch out in any steep open areas or sparse trees. Human-triggering will still be likely in these areas and the consequences of a slide in the trees are often dire due to terrain traps and trauma.
Avalanche Problem #2: Wind Slab
This weekend’s north winds created areas of wind slab on southeast-south-southwest aspects above treeline. Those slabs are cold, dry, and not bonding well. Warming temperatures and a new load of snow on top may reactivate these slabs, which would avalanche into the old snow and possibly be 30-60cm deep.
Recent Avalanche Activity
There was a natural avalanche cycle during last week’s heavy storm cycle. Some Size 4 slides occurred, some of them hitting valley bottoms. They appear to have occurred in heavily wind loaded areas at or just above the new/old snow interface.
A strong and moist front will move slowly onshore Tuesday, with heavy snowfall rates of 2-3″/hr Tuesday night. South winds will be moderate, and snow levels will probably rise to about 1000ft near town, possible staying at valley bottom up the highway. 16-24″ of new snow is possible above 1000ft, with 4-12″ below.
We had a wind event on the 20th-21st, with heavy wind loading on southeast, south, and southwest aspects and gullies/terrain features.
Snowfall totals from the 12th-19th are around 60-82″ above 1500ft (highest amounts in the Lutak zone, with less towards the Pass). Below that level was mostly rain. South winds were strong throughout, and there were brief periods of rain up to 2500ft.
Additional Info & Media
2017 New Year’s resolution – develop backcountry habits to LIVE TO RIDE ANOTHER DAY:
- everyone in my riding group has a functioning beacon, probe, and shovel (& floatpack)
- my group chooses to avoid slopes with rocky trigger points
- my group chooses to avoid slopes with terrain traps; cliffs, gullies, and creek ravines
- my group agrees that one rider on a steep slope at a time is what we do
- my group gathers out of harm’s way, beyond the run-out
- my group reviews our day – where could we have triggered a slide? how can we improve our plan?