Marmot

Skied Ullr's couloir today. Wind was consistently strong from the SW. Wind transport was limited to facets and shale. Large cornices loom and block all the chutes and couliors along the ridge except ullrs. Cornices are very hard and didn't want to move. Temp was below freezing, no solar effect wet loose activity started on solar aspects by the time we skied. Thin (5-10cm) windslab isolated to immediately below ridgecrest and on cross loaded features lower in the couloir. Some sluffing of 10 cm of soft surface snow through the rest of the line. No other snow stability concerns.

Recent natural activity on east-facing steep alpine slopes. Great snow quality in Marmot Bowl, and at/below treeline toward Indian Pass. Shallow snowpack in the pass, occasional whumpfing.

Rode a few laps on both sides of marmot pass. Good snow quality at treeline and in gullies made for some fun turns. Wind affected and crusty in the alpine.

Widespread wind affect in all ALP and exposed TL features. Snowpack generally weak and facetted in sheltered areas but still supportive (mostly) under skis. HS 0-115cm. No signs of instability. No recent avalanche activity. Field wx: Few clouds with L, SW winds and -11C.

Went up and over Marmot Pass from North to South. Very windy at the pass. Good riding conditions down from the pass towards Portal. Stuck to mellow playful slopes in the sun.

Recent upslope storm created unusual windloading patterns on ALP solars (Indian Peak) which caused for variable ski conditions and a very significant whumph @2300m. In sheltered north-facing alpine terrain between 2200-2500m, conditions were much more favourable (no windslab and good quality skiing) which allowed us to ski terrain up to 40 degrees. Snowpack consisted of an HST of 3-5cms sitting atop buried windslabs and facets. Average HS: 85cms. No new natural avalanches were observed. Winds were L, SW with mostly clear skies and temps just below 0.

Tour up Franchere Valley. Very shallow snowpack throughout (HS 0-120cm, HST 2cm). Old windslab was widespread throughout the ALP with weak basal FC/DH below, which was reactive to skier traffic in isolated locations (whumphs). No new Na observed. Winds were L-M, SW, with L ridgetop blowing snow from the west. Temperatures remained below -10C in the ALP. Snowpack at TL facetted and mostly unsupportive on skis.

Conditions seemed generally good today for travel in a wide variety of terrain in whistler creek, but there are isolated instabilities. Best snow is sheltered, low angled lower alpine and treeline. Variable previous wind affect in many places. Steep aggressive lines had been skiied on various aspects the previous day (colder). We rode one large, steep E facing alpine slope today (the majority of which had previously avalanched, while avoiding large areas thay hadn't slid this season), but backed off another objective due to shooting cracks (5m) in a surface slab. On a steeper slope (eg further along the ridge toward ullars) this might have released as a slab Appeared to be isolated, small pockets of old windslab (now hard to discern) lee to previous north winds, sitting on facets, which appear to exist in immediate lee along the south side of ridge crests. Then in flat treeline we experienced two whoomphs while folllowing an old skin track, with shooting cracks connecting small trees. This demonstrated the midpack (thin in that area) has weakened during recent cold temps. So, generally good but in places not perfect. Surface snow was warming on even low angle SW slopes in the afternoon, though not quite moist where we travelling in the upper alpine. Cold NE breeze on the ridgetops but otherwise the sun was packing a punch, and much warmer air than previous days.

5cm fresh snow fell overnight with minimal wind affect, but snowpack depth is highly variable due to previous wind affect. We found great ski quality on supported, moderate angled terrain, and avoided large steep slopes, shallow rocky areas, and smaller convex slopes above terrain traps. Shallow spots were sometimes tricky to identify. We also ski cut small test slopes, & dug profiles at alpine and treeline elevations on Whistler Creek side of Marmot Pass area. See photos. These showed an 'upside down' snowpack structure; with a harder, more dense midpack, over a softer, weaker base of depth hoar near the ground. This was also easy (& quick) to detect in many areas simply by probing. In the Alpine on a West aspect we observed repeated Very Easy, Sudden results down 35cm on the January surface hoar/facet layer. On this aspect there was little slab overlying the layer, due to recent faceting / softening of the upper snowpack during cold temperatures, but it certainly made us consider the consequence of finding a slope where the upper snowpack is more consolidated over this layer. Sudden test results on the weak basal depth hoar, both in the alpine and at treeline, indicate there is still potential for Large, Deep Persistent slab avalanches if triggered (more likely from shallow areas or by large loads). No investigation of solar aspects (eg Portal Creek side Marmot Pass), however due to previous Northerly wind events, it is possible there is a slab over the January persistent weak layer (PWL) in places, especially near ridgetop, and we felt more wary of this terrain.

Test Pit aprox 2170m, just below TL, E aspect, aprox1300. HS 110: top 5 moist, FC below, found a heavily faceted MFcr aprox 20-30cm above ground, depth hoar at ground CTM 14, 14, (BRK) down aprox 80 (or aprox 3/4 of the height from surface) in FC 5mm, ECTX Air temp +8, surface at freezing, 10cm temp -7.5 Good skiing on E facing alpine slope, skiing out BTL on SE aspect up to 10cm moist snow on facets. Shaded or east facing pockets seemed to stay dry.