---------- Terrace & Coastal Areas ----------
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  |
Thursday |
Friday |
Saturday |
Alpine |
3 - CONSIDERABLE |
2 - MODERATE |
3 - CONSIDERABLE |
Treeline |
2 - MODERATE |
2 - MODERATE |
3 - CONSIDERABLE |
Below Treeline |
2 - MODERATE |
1 - LOW |
2 - MODERATE |
---------- Smithers & Interior Sections ----------
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  |
Thursday |
Friday |
Saturday |
Alpine |
3 - CONSIDERABLE |
2 - MODERATE |
2 - MODERATE |
Treeline |
2 - MODERATE |
1 - LOW |
2 - MODERATE |
Below Treeline |
1 - LOW |
1 - LOW |
1 - LOW |
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Confidence:
Fair. The snowpack structure is complex and varies between areas and
even between drainages. The quantity of field data is limited.  |
Primary Concerns:
-
Wind Slab: Snow and wind have loaded (and will continue to load) NW-NE slopes so watch for pockets of wind slabs on the lee
side of ridges and similar terrain features. It also means cross loaded
slopes and gulleys on more E'ly and W'ly facing terrain features. If
the NW wind blows strongly Thursday, the loading pattern will shift
towards the SE.
-
Cornice: Cornices and Overhead Hazards: Falling
chunks the size of box cars are hazardous unto themselves, but when
they trigger a slab the problem explodes, especially if nasty deep weak
layers come into play.
-
Solar Radiation:
It's April - the sun's higher and stronger. Watch for rapid warming if
the sun comes out and bakes low elevation slopes or solar aspects.
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Special Message:   Here's a photo analysis from a few recent incidents (click here).
Although they aren't from deep coastal snowpack areas, they are
instructive. There's lots of similar terrain in the NW and this winter
you lack the typical strong coastal snowpack. |
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Travel Advisory:  
Issued: Wed, Apr 1 Next Scheduled Update: Sat, Apr 4
I
continue to like terrain where the general snowpack is deep not
shallow, supported slopes where the snow is held up from below (rather
than falling off like above a cliff or where it rolls off as a slope
steepens), and consistent lower angle slopes without overhead hazards.
Watch
for wind effect: that means recently formed pillows or drifts of deeper
"slabby" snow on steeper slopes. This is the type of "soft slab"
problem where testing small slopes with minimal consequences can help
you assess what's going on and where the slabs are found - whumpfing,
shooting cracks, and small slides are what you're looking for. But
remember (1) test SMALL slopes without serious consequences (2) slope
tests don't work for HARD slabs which are unpredictable dangerous
beasts, and (3) slope tests don't tell you anything about layers more
than around 50 cm deep. You need to pull out you shovel and sniff
around to learn about deeper weak layers.
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Avalanche Activity:  
Issued: Wed, Apr 1 Next Scheduled Update: Sat, Apr 4
Recent avalanche reports from northern and interior sections are of
windslabs on steep windloaded features near ridges up to size 2.5. Open
treeline areas released smaller size 1 wind slabs and sluffs. No recent
reports from the Terrace areas. |
Snowpack:  
Issued: Wed, Apr 1 Next Scheduled Update: Sat, Apr 4
Southerly winds have created slabs on the north through east sides of
exposed ridges and similar terrain features. This snow rests on crusts
(solar aspects), surface hoar (don't know too much about its
distribution but likely includes the typical shady treeline elevations
and maybe on a buried suncrust on sunny aspects), or just older storm
snow.
There are several PWLs buried deeper in the snowpack that are producing moderate to hard "pops" and "drops" in compression tests  - the depth and distribution of these layers varies across the region. The uppermost (consisting of surface hoar, facets and/or a crust) is approximately 40 cm deep in the inland section and 70-140 cm deep in the coastal part of the region.
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View Avalanche Observation Summary
(NEW!)
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Weather:  
Issued: Wed, Apr 1 Next Scheduled Update: Sat, Apr 4
Wednesday brought 10 - 25cm of snow with light to moderate S'ly winds
to the mtns around Terrace, much less snow to other areas.
Thursday: an
upper trough means flurries but little accumulations of snow. Winds
shift to the NW and may strengthen. Cooler temperatures with freezing
level around 300m.
Friday: Dry with clearing skies possible later in the day. Slightly warmer with freezing level near 700m.
Saturday: another frontal system expected for the weekend. 
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Issued by: ilya storm
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