Haines Avalanche Center
Above 2,500ftModerate
1,500 to 2,500ftModerate
Below 1,500ftLow
Degrees of Avalanche Danger
Avalanche Problems
Problem 1
The Bottom Line: The main threat for now is stiff wind slabs, from several days of strong NW winds. Any recently wind loaded areas may harbor wind slabs 1-2ft thick which could be triggered by a human (Think cross-loaded gullies, and also aspects lee to the NW wind). These surface wind slabs could also step down to rain crusts or the ground in particularly weak areas. (See Persistent Slab problem below)
Wind loaded slopes and cross-loaded gullies should be avoided or carefully managed. You can tell if a slope is wind loaded by the filled-in, rounded or pregnant shape of the snow. Probe around for hollow, slabby surface snow. Minimize your exposure to these slopes, and always travel one-at-a-time through any suspect areas. Rocks will be a major safety hazard as well, so take it slow and easy, and keep your avalanche eyeballs on, especially in wind loaded areas and convexities!
Likelihood:
- Almost Certain
- Very Likely
- Likely
- Possible
- Unlikely
Size:
- Historic
- Very Large
- Large
- Small
Trend
- Increasing
- Steady
- Decreasing
Problem 2
— We are in an Assessment Mindset regarding the following buried weak layers: —
Midpack Melt Layers and Crusts:
There is a unique weak layer forming in the midpack, about 60cm deep (The “Big Warmup” Layer). It initially was a thick layer of warm melting polycrystals from the Nov 17th warmup, but has since frozen and begun facetting into an unusual weak layer with low predictability.
Observations from 12/1 in the Lutak zone found high strength but good propagation on failures within this layer. We know it to exist at all elevations above 1000ft — even up to the highest summits. We expect this layer (or other midpack crust-facet layers) to be an ongoing issue going forward.
Depth Hoar Formation:
The November cold snaps created basal facets in thin areas above 1000ft. These facets haven’t been active yet, but the possibility still exists that an avalanche could fail at the ground in thin areas with a slab on top. This concern may grow into a deep slab problem over time if these facets weaken into depth hoar.
Pit photo from Lutak zone 12/1, and profile from 11/26.
Likelihood:
- Almost Certain
- Very Likely
- Likely
- Possible
- Unlikely
Size:
- Historic
- Very Large
- Large
- Small
Trend
- Increasing
- Steady
- Decreasing
Weather
Forecast:
Friday looks clear, cool, and breezy as another push of arctic high pressure slides by into BC. Saturday and Sunday are looking downright balmy in the mountains. We are expecting light winds, clear skies and a strong inversion with cold temperatures stuck in the valleys but warming well above freezing in mountain areas.
Seasonal Summary:
- An arctic outbreak brought very cold temperatures and strong NW winds Nov 27-Dec 2nd
- Nov 20-25 brought about 2ft of new snow above 2000ft (about 1ft in the Pass zone)
- Mid November was very warm, with temperatures reaching over 40F at 5000ft
- Cold weather set in Nov 4th – 9th, with alpine temps down to 8F at times
- A NW wind event Nov. 6th blew away much of snow in exposed areas
- 2 to 3ft of snow fell in Early November down to sea level
- October 26-27th brought in 5-12″ of heavy wet snow above 1500ft
- The first layer of snow to remain into winter fell above 3,500ft on Oct 21st. It was 6-12″ deep.
Snow Depth [in] | Last 24-hr Snow/SWE [in] | Last 3-days Snow/SWE [in] | Today’s Freezing Level [ft] | Today’s Winds | Next 24-hr Snow/SWE | |
Mount Ripinsky @ 2,500′ | 48″ | 0″ / 0.00″* | 0″ / 0.00″* | 0′ | mod, NW | 0″ / 0.00″* |
Flower Mountain @ 2,500′ | 28″ | 0″ / 0.00″ | 0″ / 0.00″ | 0′ | mod, NW | 0″ / 0.00″* |
Chilkat Pass @ 3,100ft | 4″ | 0″ / 0.00” | 0″ / 0.00″ | 0′ | mod, NW | 0″ / 0.00″* |
( *star means meteorological estimate )
Additional Information
It’s time to start thinking avalanche. Dust off your gear and make sure it is fully functional. Put new batteries in your beacons! Do a beacon practice to start the season and keep your skills fresh.
If you head into the hills, watch out for avalanche prone areas, and be especially careful of rocks and hidden hazards like crevasses beneath the snow. WEAR A HELMET!
Announcements
We have begun regular forecasting for this winter (Fridays-Sundays). Click the Full Forecast link below to read more. Please submit your observations if you head out into the hills!