Tag: backcountryskiing

Quiet interlude, then a March roar

March 10th, 2025
0400 wx. at 6350′ in Carnelian Bay: 30.2°F / 20.8°F dew point / 68% RH / calm winds

0515 obs. at 8650′ Mt. Rose backcountry TH: 27°F / light SW winds

0600 ob. at 9200′ in Mt. Rose backcountry: 28.7° / -1.5° dew point / 27.1% RH / high overcast / SW winds at 10mph, gusts to 14mph

Backcountry obs.:

Backcountry conditions this morning reflected a typical spring interlude between storm systems: melt-freeze crusts and powder, depending on aspect.

Any patch of snow receiving direct sunlight over the weekend has undergone a melt-freeze cycle leaving both supportable and unsupportable crusts on the snow surface. SE-S-SW aspects hold supportable crusts and corn snow from below treeline to the alpine. Breakable sun crusts with challenging skiing exist on E, W, and NW aspects. And despite the warm temps., cold snow is still hanging on in sheltered N-NE facing zones below and above treeline.

There’s still fun snow sliding to be had at all hours if you sniff out the right zone at the right time. But conditions will soon change, likely for the better in the coming days.

Weather and forecast thoughts:

One of the most impactful storm sequences of the winter is taking aim on the Sierra for midweek through next weekend, bringing multiple rounds of heavy snow to all elevations above 6000′. This may be one of the last good opportunities to build the snowpack before the onset of spring.

Today and tomorrow (3/10-11), a weak system off the SoCal coast will bring partly to mostly cloudy skies with near to slightly above average temps. in the upper 30s to mid 40s above 7000′. Breezes out of the SW will add some chill, especially near and above treeline and along ridges. Lows tonight and tomorrow will be in the upper 20s to low 30s.

The first large storm of the series begins in earnest Weds (3/12) morning with strong SW winds and snowfall overtaking the area by mid morning. Snowfall rates look to pick up throughout the day with intensities of 2-4″ per hour possible throughout the afternoon and into the evening, especially along and west of CA 89.

Highs won’t get out of the 20s above 7000′ on Weds, and will fall through the night into Thurs (3/13) with the passage of a strong cold front. Behind the front, a cold, unstable air mass will promote intense, convective snow showers that could yield additional significant accumulations through the day on Thurs. Temps. on Thurs will struggle to climb into the middle 20s above 7000′.

Models indicate enough cold air for snow-liquid ratios (SLR)s to start out around 8:1, then increase to 15:1 towards the end of the storm. This will create a right-side up snow structure with dense snow at the base, and lighter fluff near the top.

By storm’s end, 1-2′ look likely near lake level with 2-3′ above 7000′. Some areas along the crest could receive 4′, especially if favored by convective bands throughout the day Thurs.

Snow tapers off for a few hours on Thurs night and into early Fri (3/14) morning under a cold air mass, before another storm arrives later Fri morning into Fri night. Snow levels with this second, quick wave will start out and remain below 6000′ for the duration of the storm. Another 6-12″ could fall on the backcountry by daybreak Sat (3/15).

And there’s more! The gravy train keeps rolling with another significant storm on the horizon for Sun – Tues (3/16-18), bringing more heavy snow to the Sierra.

It took a bit, but the March lion might finally find its roar.
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Bluebird Sierra spring weekend; more winter on the horizon

March 7th, 2025
0600 wx. at 6350′ in Carnelian Bay: 20.1° / 16.3° dew point / 84% RH / partly to mostly cloudy skies / light NW winds

Backcountry obs.:

While the second storm in this week’s series dropped meager accumulations around lake level communities, it delivered to the backcountry. Yesterday (3/6) at dawn, west shore zones along highway 89 received between 4″ at 6900′, to up to 14″ just beneath the peaks near treeline at 9100′.

The new snow rested right-side up atop saturated, refreezing melt-freeze crusts. Accumulations grew quickly with height on NE aspects. Some minor wind texture adorned surface snow, mainly at higher elevations near treeline, but with negligible effect to ski quality. However, near treeline, wind pillows on lee slopes and rollovers did react, producing shooting cracks, propagating fractures, and some minor wind slab avalanches. I observed one such skier triggered wind slab avalanche that ran like a teardrop a few hundred feet down an open E face. The slide entrained the slab and surface snow, running on a bed of firm, melt freeze crusts. No skiers were harmed.

Instability aside, the new snow skied great throughout the morning. Cold, right-side up fluff skied fast and smooth, providing long, high speed, powdery arcs on open NE faces. Down low, slower, shorter turns bottomed out on firm, pre-storm bed surfaces. However, the moist, decomposed nature of the crusts dampened any jarring contact of ski to crust providing excellent turns from summit to trailhead.

Another March morning delivered.

Weather and forecast thoughts:

This morning dawned cold under a mix of clouds and sun behind the departing storm system. Today a brisk NE flow will bring gusty winds and cold temps to the backcountry. While the cold temps. will help preserve the snow from the intense sun, brisk winds may strip new snow from near and above treeline on N and E facing aspects. Highs today will largely remain in the 20s above 7000′.

Tonight a ridge of high pressure begins to move into the region moderating winds, temps., and clearing skies. Lows tonight will drop into the teens under clear skies and slackening winds, setting the stage for a mild and sunny weekend.

The main headline this weekend (3/8-9) is the return of Sierra spring: warming temps. and sunny skies. After a cold start on Sat., temps will warm into the middle to upper 30s across the backcountry under sunny skies with light winds. Rinse and repeat for Sun. Lows both Sat. and Sun. night will drop well into the 20s with inversions looking likely each night.

Spring-like weather holds on for Mon. and Tues. (3/10-11) with mild temps. in the 30s to low 40s above 7000′. Clouds will be on the increase Mon. as a system impacts SoCal, but largely misses the Sierra. Tues. winds and clouds should increase ahead of another more impactful winter storm taking aim on the Sierra.

By early Weds., a significant winter storm looks likely to begin impacting the Tahoe Sierra through early morning Fri. Most models and ensembles show a high probability for 1-2′ of new snow at lake level, with considerably more (2-3′) into backcountry zones across Tahoe. Snow levels are also trending lower, remaining below 6000′ for the entire event. This storm has been showing up in models for the past week, which does tend to boost confidence, however it’s still at least five days and much can change as the details come into greater focus.

Beyond the mid-week storm, long term forecasts show more systems impacting the region with temps. remaining below average. CPC models show below average temps and above average precip. impacting the Sierra through the third week of March.
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Back to winter

March 3rd, 2025
0400 wx. at 6350′ in Carnelian Bay: 26.1° / 22.1° dew point / 84% RH/ 2″ new snow.

0515 wx. at 7140′ west shore TH: 23°/ 4″ new snow

0630 wx. at 8640′ pinnacle along the Sierra Crest: 18.3° / dew point 16.2° /relative humidity 95% / over cast with light freezing fog / SW winds at 7 mph, gusting to 10 mph

Backcountry obs.:

The backcountry is in transition back to winter! This weekend, a morning tour on southerly aspects in the Mt. Rose area revealed very springlike conditions with refrozen melt freeze crusts at dawn, softening to smooth corn by mid morning. By afternoon on Sat. (3/1), warm temps. baked solar aspects into thick, over ripened corn, sliced and diced with deep trenches by snow sliders.

Rapidly falling temps. associated with the arrival of a weak storm late Sat. refroze all old snow surfaces into hard crusts by evening. On Sunday, the system dropped a light refresh of dust on crust, mainly near the Sierra crest, with lower elevation and eastern zones receiving barely a trace.

This morning (3/3), a predawn tour along the west shore up to the Sierra crest revealed 6-8″ of new, moderate density snow resting atop frozen crusts from the recent warm period. Some wind affected surfaces existed near treeline along ridges, but coverage was minimal and confined to only the most exposed ridge features. Animal tracks left from the overnight hours remained fresh and unaffected by wind throughout forested areas in the new snow.

The new snow felt generally right-side up and did not evidence any obvious instabilities. Turns on sheltered, NE aspects were mainly fluffy, bouncy and smooth with only a few scrapes along underlying crusts on wind-exposed features. A sneaker pow morning, indeed.

Weather and forecast thoughts:

The weak storm that began impacting the area on Sunday (3/2) has departed this afternoon (3/3), leaving cool temps., clearing skies, and a few inches of new snow across the Tahoe backcountry.

Tonight will be clear and cold with lows in the teens and low 20s above 7000’.

Tomorrow (3/4), skies will start out mostly sunny, before a weak frontal system ushers in SW breezes, increasing clouds and chances for snow showers into the afternoon and evening. Any accumulations will be an inch or less tomorrow. Highs above 7000′ should top out in the mid 30s.

Another weak to moderate system is poised to move into the area later Tues. pm through Weds. and into Thurs., bringing chances for more snow, especially from Tahoe southward. Models as of this afternoon indicate growing confidence in the development of a cold Tonopah low, which, with a little luck, can bring surprising amounts of cold snow to the Sierra, especially to the Carson Range. 6-12” of cold, light snow looks very possible for the Tahoe backcountry Weds.-Thurs. afternoon (3/5-3/6). Locally higher amounts could materialize depending on the strength and positioning of the low.

Another break in the action rolls in for the weekend with mostly clear skies, light winds and cool temps across the backcountry for Sat. and Sun. (3/8-3/9). Temps. will warm on Sun. approaching the low 40s for backcountry areas near and above 7000′.

As the weekend winds down, models show another parade of storms rolling through next week, potentially more significant than the modest refreshes this week. While timing and specifics still vary from model to model, the overall trend across is for wetter and cooler than average conditions. Additionally, signals for stronger, cold storms throughout the week are consistently showing up across model runs. Confidence in at least one significant storm is growing, but clarity on specifics remains elusive. Winter has more to give.
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Tag: backcountryskiing

Quiet interlude, then a March roar

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Bluebird Sierra spring weekend; more winter on the horizon

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Back to winter

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