Tahoe Backcountry Snow

0400 temp. at 6350′ in Carnelian Bay: 24.1 deg.

Trace new snowfall

0515 temp. at 8650′ Tamarack TH: 17 deg.

Backcountry obs.

Skiing in the Rose backcountry continues to improve and stabilize as of this morning. Stability improvements may be short-lived as wind slabs grow due to an incoming disturbance bringing modest snowfall and moderate/high winds. Snow totals for the next 24 hours could reach 6″ along the crest and west of the lake, while eastern zones will likely see a few inches.

Moderate to strong winds out of the WNW and cold temps welcomed the day in the predawn hours at the Tamarack TH. No appreciable new snow fell in the past 24 hours, but surfaces on all aspects remain soft and have further consolidated from the upside-down snow left in the wake of the weekend storm. Wind effect on surface snow was notable with modest soft texture in treed and protected zones, to soft, easily turnable buff on direct windward aspects. Ridges are becoming sculpted and firm, but cold temps and new snow are redistributing the fluff rather than allowing winds to deeply scour surfaces.

Thus far this season, this is the week to be in the backcountry. Protected steeps and bowls have cold, fast fluff atop a springy, dense base making for soft, floaty turns. Surface conditions are largely consistent, so opening it up with confidence is easy. Midwinter snow depth also means that the early season sharks have migrated down below 7000′.

Forecast and weather thoughts:

Today a weak system will bring moderate winds and generally light snowfall to the region. A reinforcing shot of cold air will accompany the storm, keeping temps. in the low 30’s around the lake, low 20’s in the mountains. Expect generally gray and overcast conditions, but a few peeks of sunshine aren’t out of the question. Snowfall totals through tomorrow morning will range from 1-3″ around the lake to up to 6″ up along the crest. The backcountry should receive a modest surface refresh.

The remainder of the work week still looks to feature periods of light snowfall and cold temps as a couple weak impulses drop into the trough of low pressure that currently sits over the region. As the trough lazily moves eastward, each successive impulse will take a more eastward track becoming progressively drier. The result: a few light snow showers, shots of colder air and breezy conditions eventually giving way to sunshine by Saturday.

The weekend will initiate a calm period of clearer skies and modestly warmer daytime temps in the upper 30’s around the lake, 20’s in the mountains. Drier air will likely still preserve sheltered snow hopefully keeping the backcountry powdery through the weekend on NW-E aspects.

The Sierra looks to remain under the influence of high pressure for the coming week which will translate to fair skies, seasonal temps, and little to no chance of new snow.

Looking way out into the Pacific next week, models show the jet stream remaining strong in the central Pacific and beginning to extend towards the the west coast at the end of the week. What that means is anyone’s guess at this point: too far out.

For now, the gettin’s good. Best to treat this week as the best it could get all season.

0430 temp. at 6350′ in Carnelian Bay: 28.8 deg. & 98% RH

1-2″ new snow

0515 temp. at 8650′ Tamarack TH: 18 deg.

2-3″ new snow

Backcountry obs.:

Skiing has vastly improved in the past 24 hours. Cold temps, cloudy skies, and few inches of new snow have primed the backcountry for brilliant mid winter pow skiing. Fast, light surface snow, combined with a dense, springy base underneath made high speed, elongated pow turns and playful pops over pillows and features feel effortless.

Cloud cover and cold temps. expected today should preserve conditions and maintain the trend towards improving post-storm stability.

Overcast skies, cold temps, and very light winds graced the backcountry this morning. A dusting of 2-3″ of new, cold snow filled yesterday’s tracks. Areas of patchy fog and low clouds drifted gently through the forests and along the ridge tops all morning.

The recent storm snow has begun to settle and consolidate. Vigorous pole plunges still easily reach 1-2′ deep. A few density changes are noted when probing, but they are more subtle than yesterday. Outside the skin track, skis drop in about 3-6″ into the snow when breaking trail without a collapsing trap door feel. Surface snow is cold and light with supportable, dense storm snow beneath.

Winds were very light this morning from the TH to the summit. Soft surfaces without wind texture extended all the way to above treeline terrain.

No obvious signs of instability were noted today. It feels like the snowpack is settling down.

Weather and forecast thoughts:

Today cold temps and cloudy skies will prevail across the region with a few snow showers developing from late morning through the afternoon. New snowfall amounts should be less than an inch in mountain communities up to a couple inches in the backcountry. Tonight will be cold and cloudy with stray showers passing through. Little accumulation can be expected tonight. Temps today will range from the low to mid 30’s around lake level to low to mid 20’s in the mountains above 8000′.

Weather the rest of the week will be similar to today with chances of snow showers each day and seasonably cold temps in the 20s and 30s. Temps. cool off a degree or two Weds. – Fri with another impulse of energy passing through late in the work week with the potential to drop a few more inches of cold snow on the mountains. Winds look to remain light.

A large scale trough of low pressure in the wake of the weekend storm is slowly moving W to E across our region. The trough allows small surface low pressure systems to drop in from the N and W generating instability and a few snow showers as they pass. Additionally, each wave will bring a modest reinforcement of cold air. Expect this pattern to keep backcountry snow conditions in excellent shape through the work week.

As the trough progresses east at the end of the week, a final shot of light snow and cold air will drop in late Thurs./Fri. before a ridge of high pressure begins building for the weekend and next week. The ridge will deflect Pacific storms to the N and S of the Sierra and modestly warm temps. This weekend could be sunny and bluebird.

Models indicate the ridge of high pressure holding on for next week keeping our weather fairly quiet.

Get it while you can.

0430 temp. at 6350′ in Carnelian Bay: 30.9 deg. and falling w/ 98% RH

10″ new 24hr. snow. (19″ storm total so far)

0515 temp. at 8400′ Incline Peak TH: 24 deg.

18-30″+ new snow between TH and 9500′ summit

Backcountry obs.

Travel was slow going this morning in the backcountry. Strong S-SW winds and bands of intense snowfall greeted the day reducing visibility and making travel disorienting. Breaking trail up Incline Peak was deep and arduous, made more so by a noticeably upside down snowpack. The lack of any rain crusts and cold, soft snow suggest that yesterday’s warming temps did not crest freezing in this zone. The warm up is clearly evident in a “trap door” snow pack that is noticeably more dense on top than underneath.

New snow amounts increased with elevation and protected areas below treeline held soft snow without much wind effect. The denser snow is about 1-3″ thick at the top of the snowpack, with feet of colder, lighter snow beneath. At and above treeline, ridges have firm cornices and wind pillows that don’t extend very far downhill.

Surprisingly, ski cuts and stomps did not release any wind slabs. Cracking, whumphing, and other obvious signs of instability were not observed. The amount of new snow and its upside down nature were strong enough warnings to avoid avalanche terrain and stick to more mellow, protected areas.

The skiing this morning was great fun, but strenuous. The depth and density of the new snow, coupled with the need to stay off steep terrain discouraged any turning beyond wide steering at speed. Float is the name of the game until the new snow consolidates. If you own pontoons, today would be a day to use ’em.

Weather and forecast thoughts:

The rare low pressure system responsible for yesterday’s storm produced a wide variety of impacts around Tahoe. Snow started before dawn on Sun. with cold temps that inched upward throughout the day. At 8am I recorded 9″ of cold, light new snow at 6350′. By 1pm, temps had just barely edged above freezing and 9 more inches of snow had fallen. Around that time, snow began to taper to showers and temps slowly climbed. By 5 pm, winds increased dramatically and temps continued rising, but more rapidly. By 9pm temps had climbed to 37.6 deg., the high temp. for the day. By this morning, freezing temps. returned along with bursts of heavy snow.

This storm has been yet another reminder of how different and unpredictable each storm can be. Despite all the advanced modeling now available, we never really can know what the future will bring until it’s upon us, especially in an area as varied and dynamic as the Sierra. Slight adjustments in track, ocean water temps, or some distant atmospheric variation can greatly impact how storms interact with the Sierra’s topography, and how much snow falls – or doesn’t – from one area to the next.

Today snow will continue to fall in intense bands throughout the morning and into the afternoon and evening. Temps. will be a bit cooler, keeping snow levels down to lake level throughout the day. Peak temps. will happen around or just after midday, before falling off as the sun’s angle wanes. Tonight a few snow showers are still expected with colder night time temps.

New accumulation today will be highly variable depending on where intense snow bands set up. Some areas in the backcountry, especially along the crest and in the higher terrain, could see an additional foot. Mountain communities should see between 1-6″.

Tomorrow cold temps and snow showers will continue with highs in the low-mid 30’s in town and lows in the 20’s.

Chances of snow showers and cold temps stick around through the work week before calmer weather settles in for next weekend. No big warm ups are on the horizon with high temps in the low to mid 30’s and lows in the 20’s. Backcountry areas will see temps in the 20’s and teens. A moderate warming trend may arrive with calmer weather this weekend.

The snow might be weird, but it’s here. Time to get it.