Early November Update

Issued: Tue, Oct 31, 2017 at 8AM

Expires: Sat, Nov 04, 2017

We will be providing an AIARE Avalanche Level 1 Class this winter in Haines, February 23-25, 2018

More info and signup here.

Above 2,500ft None

1,500 to 2,500ft None

Below 1,500ft None

Degrees of Avalanche Danger ?

1. Low
2. Moderate
3. Considerable
4. High
5. Extreme

Avalanche Danger Rose ?

Avalanche Problems ?

Problem Details

Avalanche season is here. We’ve already had a significant skier-triggered avalanche reported (see below). Early season can be sketchy: several avalanche fatalities have occurred this time of year.

Snow depths are around 15cm at 3,500ft, ranging up to 100cm in wind loaded areas above 5,000ft. October brought less than half of the normal 9″ of precipitation we would expect for the month. The result is quite variable snow depths due to thin snowpack and windy conditions.

Our first arctic outflow event will come in for the first week of November. Temperatures above treeline will drop to around -12°C (+10°F). This is bound to cause faceting of the thin snowpack above treeline, setting up a weak base to hold up future heavy snows. Keep this in mind as November progresses and snow depths increase.

For now, keep your guard up, and feel around for slabby, layered snow which may be unstable. Probe and dig around. If you find cohesive slabs sitting above softer, weak layers, you have everything you need for an avalanche. Remember that conditions are quite variable right now, and stability will vary from slope to slope. Start the season with fresh batteries in your beacon, and practice with your beacon, shovel, and probe.

If you get out on the snow, send in your observations! We will start regular forecasting when enough obs start coming in.

Recent Avalanche Activity

SS-AR-D2-R3-S | A snowboarder-triggered D2, Nadahini-area, 10-28-2017

October 28th: First rider-triggered slide reported from the peak north of Nadahini (“Sunny Bunny”). D2 soft slab ran in storm snow from Oct 26-27. Nobody caught or injured. [ SS-AR-D2-R3-S ] South aspect @ 6,200ft.

Small – Moderate natural avalanche activity is occurring during/after storms. So far it has been mostly loose-snow slides, with a few slab avalanches as well.

Recent Weather

Arctic outflow will begin Tuesday, with alpine temperatures falling to around -12°C (+10°F) for most of the week. Moderate to strong north winds will cause blowing snow and fresh wind loading on south aspects. The next possible storm will be around Sunday-Monday. Cold weather looks to continue.

 Snow Depth [in] Last 24-hr Snow/SWE [in] Last 48-hr Snow/SWE [in]  Today’s Freezing Level [ft]  Today’s Winds Next 24-hr Snow/SWE
Mount Ripinsky @ treeline

2

0 / 0.01 0″ / 0.01 3,000  mod, N  0 / 0.00 *
Flower Mountain @ treeline

 6

 0 / 0.07  0 / 0.07 3,000 mod, N  0 / 0.00 *
Chilkat Pass @ 3,500ft
 6 * 0 / 0.05 * 0 / 0.05 * 3,000 * mod, N  0 / 0.00 *

( *star means meteorological estimate )

October 5th: 4-10″ of snow fell above 4,500ft.

October 13-15th: 6-12″ of snow fell above 2,500ft in the Lutak and Transitional zones, less snow fell in the Pass zone.

October 18-24th: 2-6″ of snow fell above 2,000ft

October 26th-27th: A warm tropical system brought heavy snow above 3000ft, transitioning to heavy rain as snow levels peaked near 6000ft before dropping again. There was a net gain of around 30cm of new snow above 5000ft.

Additional Info & Media

Posted in Transitional Zone Forecasts.
Erik Stevens

Forecaster: Erik Stevens