Tahoe Backcountry Snow

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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Taste of spring before winter’s return; and a note about NOAA

February 28th, 2025
0500 wx. at 6350′ in Carnelian Bay: 33.1° / 22.6° dew point / mostly clear skies / calm winds

Backcountry conditions:

Snow in the Rose backcountry over the past week has been largely stable and spring-like. Cold mornings have refrozen snow surfaces into hard melt-freeze crusts that soften each morning and early afternoon under warm temperatures and mostly sunny skies.

Nights have been largely clear and dry, promoting efficient cooling and below freezing temps on snow surfaces. On Thurs. morning (2/27) at 0630, I observed air temps at 1.5m above the surface at 34.5° on the summit of Tamarack Peak, while temps on the snow surface registered 24°. The dry airmass and evaporational cooling, along with clear skies, helped keep snow frozen even in above freezing temps!

As previously noted, timing and aspect selection are key to finding the perfect snow softness in this spring regime: too early and snow is hard and chattery, too late and it’s all mush and sweaty mashed potatoes.

Weather and forecast thoughts:

Change is a’comin! Spring will hold out today and tomorrow (2/28-3/1) with mostly sunny skies and warm afternoon temps into the upper 40s to near 50 throughout the Tahoe backcountry. Overnight Sat. and into Sun., a modest, yet cold storm will move into the area bringing a quick hit of snow to the area, likely refreshing backcountry surfaces with cold, soft powder.

Timing for the Sun. storm has recently pushed back a bit, with the most impactful snowfall rates coming throughout the day on Sun., tapering off in the evening. Current models show the storm favoring areas along the crest from Tahoe southward. Expect anywhere from 2-8″ of new snow by Mon. morning (3/3), with highest amounts falling along the crest and south.

SW winds will increase as the storm moves in on Sat. night and early Sun., although they look fairly modest by Sierra standards.

By Mon. (3/3), the storm moves out leaving cooler temps., partly cloudy skies, and lingering snow showers in its wake. Expect highs above 7000′ in the 20s to low 30s for Mon. and Tues.

A more significant storm — yet still not a whopper by Sierra standards — looks likely for the middle of next week: Weds-Fri. (3/5-3/7). This one is again looking cold, bringing additional snow to all backcountry zones above 6000′. As of today, the mid-week storm looks to favor areas from Tahoe southward.

Luckily, the pattern looks cold and wet heading into the middle of March, with more opportunities for larger systems to impact the Sierra and boost snowpack. Current extended outlooks show high probabilities for above normal precip. and below normal temps.

Most years the Sierra crescendos throughout March and into early April. The best is still yet to come…

A note about NOAA and NWS:

Yesterday, hundreds of federal employees at NOAA and NWS were summarily fired by DOGE and the Trump administration. This first round of firings affected probationary and temporary employees, those who are either recent hires or recently promoted to senior level positions. The jobs lost affected people across the board, including data scientists, hydrologists, and shift meteorologists at local NWS offices. Fire weather forecasters and incident meteorologists were not spared either.

The losses and impacts on the public will be significant. Many of the lost positions are mission critical to protecting public safety and infrastructure around the country. The work of NOAA provides the backbone for our understanding of the climate: how to stay safe, prosper within it, and adapt to a changing future. Since their inception, these agencies have provided a critical public good enjoyed by all Americans.

More RIFs (parlance for ‘reduction in force’) are imminent across NOAA and NWS with public plans of nearly 60% of the total workforce being dismissed in the coming year. Yesterday was just the first round.

If you appreciate the work of NOAA and NWS and want to do something, please contact your respective member of Congress by phone and voice your opinion directly. Ask them to advocate for our local forecasters and public that benefit from their work.

In the Sierra, those representatives are Mark Amodei of NV (775-686-5760) and Kevin Kiley of CA (916-724-2575).

Thank you.
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Bluebird Sierra spring weekend; more winter on the horizon

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Back to winter

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Taste of spring before winter’s return; and a note about NOAA

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