Tahoe Backcountry Snow

0430 temp. at 6350′ in Carnelian Bay: 31.7 deg. & 89% RH

Backcountry obs.:

No real backcountry obs to speak of over the past few days beyond touring inbounds at Diamond Peak. Early morning backcountry conditions have remained consistent with hard, heavily rutted and tracked out surfaces until softened by sunlight and daily warming. Lows each night have been around freezing at lake level and well below higher into the mountains. The spring skiing has been a hoot, but changes are afoot…

Weather and forecast thoughts:

Today may be the last mainly dry day for a while as a trough of low pressure moves into the Sierra bringing a new round of snow over the weekend. A mix of clouds and sun will start out today before clouds thicken, winds increase and precip. starts late this afternoon into the evening. Snow levels will start above lake level (7000′ or so), then quickly come down after a frontal passage late in the evening. Expect highs today to reach the upper 40s around the lake. Tonight’s lows will drop into the 20’s allowing for snow to accumulate and the backcountry to get a complete refresh. By tomorrow morning, 2-6″ are possible in mountain communities while 4-10″ may coat the mountains with higher amounts near the crest.

Tomorrow will be cool with highs in the mid 30’s and rounds of snow showers, picking up again in the afternoon with the influence of convective instability. There won’t be a ton of accumulation in town with the high sun angles, but the mountains could pick up a few more inches throughout the day.

Sat. PM into Sun. snow continues as a cold, moist, unstable flow off the Pacific will likely deliver several more inches around the region, refreshing the mountains. Another pulse of energy hits the mountains Sat. night bringing in another few inches. And Sun. afternoon’s daily convective warming may enhance snow showers yet again, adding to snow totals. By Mon. morning, a foot or more is very possible in the backcountry around the Tahoe Basin, with locally higher amounts along the crest and in the higher mountains.

The beginning of next week tends to favor a reprieve, but the spigot won’t turn off entirely. Snow showers and cool temps look probable through Thurs. when another storm impacts the mountains bringing more snow. Early indications show a system of similar strength to the Fri. – Sat. storm this week.

Right on the heels of the Thurs. system, another, potentially more robust storm comes in on Fri. and Sat of next week, bringing yet another round of glorious snow. Both the GFS and the Euro are in good agreement for next week’s stormy pattern to continue, adding to forecaster confidence.

Powder season ain’t over yet…

0600 temp. at 6350′ in Carnelian Bay: 32.1 deg. & 99% RH

Backcountry obs.:

Not too much is happening in the backcountry outside of daily melt/freeze conditions. Yesterday morning temps in the Tamarack bc fell well below freezing (25 deg. at 5:30am at 8650′ TH). Conditions were pretty firm and poor around dawn. The area is heavily tracked out with deep ruts and tracks, frozen in place by the nightly refreeze. Shady aspects are crusty and wind affected, while solar aspects had a solid melt/freeze crust that had matured into refrozen corn snow on the most sun exposed slopes.

With daily highs getting into the 40s under strong sunshine, I suspect the skiing is quite good from 0900-1200, depending on the aspect. Conditions don’t look to change until snowfall returns to the area this weekend, resetting the snowpack back into a wintry condition.

Forecast and weather thoughts:

Warm, sunny days and cool nights have dominated Tahoe weather this week and will continue until Fri when winter returns, likely hanging out through the rest of the month. Highs for the rest of the week will hit the low 50s in town, with overnight lows near freezing, especially in depressions as inversions return until the upper airflow begins mixing out the lower atmosphere Thurs. and Fri. ahead of the pattern change.

Fri. the ridge of high pressure responsible for the spring reprieve breaks down and is replaced by a long wave trough along the west coast. This will set the stage for cooler and more unsettled weather starting Fri – Sat. as a system within the larger pattern could bring up to 12″ of new snow along the crest and 2-6″ of snow to Tahoe communities by Sat. PM.

The snowy flow continues through Sun. and into Mon., but rather than a significant dump, expect snow showers around the Basin with higher amounts in the mountains and along the crest.

We may get a break Tues.-Thurs. with cool temps holding on until the end of next week when a potentially stronger, yet fast moving storm may deliver another round of snow to the Sierra.

Don’t hang up the skis yet.

0600 temp. at 6350′ in Carnelian Bay: 35.2 deg. & 74% RH

Backcountry obs.:

It was a beautiful weekend in Tahoe as the first consistent string of sunny and warm days moved in for the first time in recent memory. Despite having mainly lackluster storms all season, the Sierra hasn’t had a stretch of clear, warm days like we often receive, even in Jan. and Feb. Reports from across the Tahoe backcountry over the weekend showed transitional snow that, despite the premature expectations for corn snow, had not yet fully transitioned and in many cases was still cold and wintry. Proper corn snow needs many days of consistent melt/freeze conditions and looking back at the season, those conditions really didn’t arrive until this warm spell.

Yesterday on Mt. Tallac, veins and panels of corn existed on SE and S aspects above treeline around 1030, but did not warm particularly fast due to some passing high clouds and very light E breezes. Temps at dawn were in the upper 20s at lake level keeping the forest snowpack firm and good for travel. Higher on the mountain, more wind effected snow prevailed with only SE facing sides of gullies and bowls hosting transitional buttery snow and “baby corn”. Higher up and on shady aspects, cold, wind effected snow with nary a touch of warmth filled bowls and chutes. Despite the transitional nature of the snow, the skiing on open, solar aspects was fast, fun, and edgeable – a great intro to spring.

Weather and forecast thoughts:

Warm, spring-like weather will only amplify today and tomorrow and continue through Weds/Thurs. Spring officially arrives tomorrow with the equinox occurring at 8:06pm. Expect highs well into the 50s around the lake with sunny skies, light winds and occasional high clouds drifting through. Lows should promote surface refreezes of the snowpack, aiding in melt/freeze corn cycle.

The blocking ridge responsible for this week’s warm, dry weather will begin weakening on Weds., eventually getting replaced by a trough of low pressure dropping in from the NW over the weekend. The result will be a return to cool and unsettled weather with snow returning to areas above 7000′ by Sat. and Sun. Enjoy the warm weather now, because winter’s coming back for a while.

Next week looks like it could be even stormier with a few models showing decent storms bringing a return of appreciable snowfall to Tahoe. This pattern continues through the end of the month, hopefully resettling and bulking up the snowpack for the spring.