4:30am temp. at 6350′ in Carnelian Bay: 24.1 deg. with 89% RH
5:20am temp. at 7100′ TH in Ward Canyon: 12 deg.
Backcountry Snow Obs.:
I headed out on a tour this morning into the Ward Canyon backcountry on Tahoe’s west shore to get a sense of how the last storm came in on the crest.
Around 10 in. of new snow greeted us at the 7100′. Amounts increased up to nearly 14 in. of new snow up to the crest at 8500′. Snow character was low density, light and dry. Some snags and small trees are still poking through lower down. The earlier warm storms that dropped cement higher up in the Rose area dropped mainly rain in this area, so there is not nearly the base that other higher elevation areas currently have.
The snow skied well, but I skied mindfully keeping my tips up in the deep powder to not tag a shark. Our group also skied conservatively avoiding avalanche terrain. Yesterday parties triggered a few slides that appeared to fail on the buried persistent weak layer (PWL) lurking just below this last storm’s layer. We did observe one slide below treeline that failed on the pre-storm melt/freeze crust and the new snow on an ENE rollover into a gully. The crown wrapped a couple hundred feet across the feature and ran a few hundred feet into the gully. The party triggering the slide submitted an ob. on the Sierra Avalanche Center page.
The snow’s great, but the white monster lurks beneath.
Forecast Thoughts:
NWS Reno hoisted a Winter Storm Warning for the area for Saturday into Sunday for the next storm. We’ve been burned so far this season, but the forecast for this one seems to hold together. It also looks to be a cold storm with light dry pow throughout the event and some decent winds as well. Winds will start out of the SW, then turn around to the NW and N, so this is something to look out for in terms of loading on features and aspects that are less often associated with wind slabs.
I’m hoping for 8-10 in. at the house at 6350′ and 1-2 ft. out in the backcountry, with highest amounts on the west side of the lake above 7000′ and along the crest. Even with these amounts, the light character of the snow probably won’t open a ton of new terrain lower down below 7000′–there’s just not much of a base for it to fall on. However, maybe the grinding effect of snow grains blowing around on the ground will increase the new snow density a bit to fill in areas that don’t have a ton of snow. All in all, this one should bring more zones into play and help spread out the crowds.
Looking beyond the weekend storm, things look to remain relatively cool and unstable going into next week. More storms appear in the long range forecast for the middle/end of next week, along with another shot of colder air. Any snow that falls will be light and dry, but amounts and timing are still tough to discern.
Looking out into the Pacific, next week models show a large ridge of high pressure building from the mid latitudes of the eastern Pacific up into the Gulf of Alaska sending the jet northward, then crashing south along the west coast. This is likely going to keep funneling cold air down from the north into our area. This isn’t a scenario that tends to tap into subtropical moisture for big storms, but it could keep things cold and fluffy. Just gotta wait and see how things develop.