Avalanche Forecast

Issued: Jan 26th, 2013 9:31AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Storm Slabs and Persistent Slabs.

istorm, Avalanche Canada

Cariboos.

Summary

Confidence

Fair - Due to variable snowpack conditions

Weather Forecast

Next active system (aka storm) is not expected until Monday and is likely to arrive with lots of wind. Tuesday may be cold and dry (if you're under the arctic air) or warmer with more snow (if you're south of the arctic front).Overnight & Sunday: WIND West moderate to strong, TEMPERATURE around -10 C near treeline with freezing level to 600m possible, PRECIPITATION less than 10 cm of new snow possible.Monday: WIND NW moderate to strong, PRECIP 20 to 25 cm, TEMP -5 C but freezing level could climb again to 700m ahead of the cold frontTuesday: colder with -15 near treeline and below freezing at all elevations, light wind, and another 5 - 10 cm of snow

Avalanche Summary

No new avalanches reported from the first few sets of observations Saturday. Loose snow slides and soft slabs are running quite far and fast on the sugary facets the storm snow covers. Most reports were for small avalanches (to size 1.5) from steep terrain.

Snowpack Summary

Storm snow accumulations over the past few days are generally around 40 to 50 cm. This snow remained quite powdery & uncohesive on Friday but is starting to settle into a soft slab. That suggests the snowpack is gaining strength in most terrain, however it could change the avalanche character from relatively harmless loose sluffs to more dangers slab avalanches. The new snow covers a crust on steep S aspects and a patchy surface hoar layer on shady sheltered slopes at treeline and below. The early January surface hoar layer is down 70-90 cm. In the southern Monashees a freezing rain crust was reported on the surface Friday.

Problems

Storm Slabs

Storm snow is settling & improving most places, but I think will be increasingly touchy where it hides surface hoar or a crust. Pockets of windslab exist behind ridges and ribs where the snow is protected from a S or W wind. Watch the fat pillows.

Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.>Use ridges or ribs to avoid pockets of wind loaded snow.>Dig down to find and test weak layers before committing to a line on steep slopes in open glades.>Be cautious as you transition into wind affected terrain and avoid recently wind-loaded slopes.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

Early January surface hoar layer is patchy but has been more reactive below treeline in shaded areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Jan 27th, 2013 2:00PM