Tahoe Backcountry Snow

0430 temp. at 6350′ in Carnelian Bay: 28.9 deg. & 88% RH

0515 temp. at 8650′ at Tamarack TH: 22 deg.

Backcountry obs.:

I headed out today to see how the current sun angle is affecting the snow surface despite cold daytime temps yesterday. In general, any aspect that is open and not facing due N, now has some sort of solar crust, ranging from supportable – but barely edgeable – to breakable and able to quickly toss any backcountry traveler into dreaded combat skiing.

Cold powder is still tenuously holding on in N facing trees and in open bowls and chutes with a steep enough pitch to promote shade and weak sun angles on the snow surface. These zones are still offering delightful skiing.

As the sun rises higher in the sky with each passing day, terrain capable of preserving powder will become ever scanter. Looking ahead into the spring, the only way to score powder from future storms will be by beating the sun to the mountains. Or you could simply embrace the change of season and go for corn snow when temps warm up.

Weather and forecast thoughts:

Cool and generally sunny conditions will persist today through much of the day Weds. with highs reaching the lower 40s in mountain communities. A stray snow shower in the afternoon can’t be ruled out later today.

Late in the day Weds. a cut-off low approaches the area from the NW that will deliver a refresh of a few inches to possibly a foot of new snow to the backcountry. Peak snowfall looks to come in on Weds. night lasting into the early morning hours of Thurs. Expect between 2-6″ of snow around the Tahoe Basin, with higher amounts above 7000′ and along the crest. Behind the system moist, unstable air will promote snow showers throughout the day on Thurs. and into Thurs. night with little to maybe a few extra inches accumulating in the backcountry.

Fri. yet another cut-off low approaches the area dropping down the Pacific coast from the N. Models continue to wobble on snow amounts and impacts for our region Fri. – Sat. PM as they struggle to get a handle on how the low will amble down the coast. Today’s runs show the low staying further offshore, keeping the heaviest precip. W. of the Sierra, most likely coming in on Fri. night in to Sat. AM. Tahoe will receive some flavor of snowfall during that time period, but the intensity is all dependent upon the track of the low pressure. A solid refresh in the mountains is probable, but whether that’s 4-6″ or 12″ above 7000′ is TBD. Stay tuned and optimistic…

Behind the early weekend system moist, unstable flow continues off the Pacific into Sun. keeping chances of afternoon showers in the forecast. Temps will moderate as well with highs reaching the mid 40s around the lake. Early next week a ridge of high pressure moves in clearing skies and warming temps a bit more.

The future holds ephemeral windows of great skiing. Get it while you can.

0400 temp. at 6350′ in Carnelian Bay: 23.2 deg. & 89% RH

3/23 24 hr. snowfall: 6″ / 3/24 24 hr. snowfall: 4″ / 3/25 24 hr. snowfall: trace

0530 temp. at Tamarack TH: 17 deg.

Backcountry obs.:

Winter has returned to the backcountry. This morning, 8-12″ of cold, unconsolidated snow blanketed sheltered and N facing areas in the Tamarack zone making for excellent skiing. Light NE winds had begun massaging the snow surface along exposed ridge lines above tree line, adding a light texture to soft wind pillows. Below ridges, winds were calm and the snow is light, cold, and pristine. NE facing bowls and gullies are skiing soft and fast, delivering skiers to alpine glory.

The weekend storm dropped anywhere from nearly 2′ along the Sierra Crest to around a foot in the Rose backcountry. Cold temps, mostly cloudy skies, and intense showers on Sat. and Sun. preserved most of the snow on sheltered N and E facing terrain leaving behind a cold, right-side up snowpack that has generally bonded well to the crusts beneath.

Any areas that did receive intense March sun during breaks in the yesterday’s shower activity have a syrofoamy-feeling layer that will soon become solar crust. Despite the cold temps, the spring sun angle bakes any exposed snow into hot pow during the day, refreezing into a dense, transitional crust once back in the shadows. On open southerly aspects, this layer is fully supportable, but quickly transitions into sporty semi supportable crust under any shade or lesser angled terrain.

No instabilities were observed in steep, N facing terrain today besides minor sluffing within the top 1″ of the new snow.

Weather and forecast thoughts:

Partly to mostly cloudy skies have started off today and will prevail throughout the day. Highs will tickle 40 around the Tahoe Basin while temps remain 5-10 deg. cooler in the backcountry. A few afternoon convective showers could pop up in the mountains today adding trace amounts of graupel and snow to the snow surface.

Tues.-Weds. will be generally sunny and a bit warmer – highs in the low-mid 40s – as a transient ridge of high pressure moves through the Sierra. Expect the snow to warm and turn transitional in all but the coldest backcountry aspects.

Weds. night, a new storm looks to come in from the NW bringing a decent refresh to the area. Models today point to anywhere from 4″ in town to up to 12″ along the crest through Thurs. Expect most accumulation during the overnight hours due to the storm’s timing, but also the high March sun angle.

Unstable, moist flow will continue Thurs. PM into Fri. before another more potent cut off low approaches Tahoe from the NW. At this point, this system appears more potent than the midweek storm, but models are fluctuating day to day. Cut offs, especially in transitional seasons (spring, fall), are notoriously difficult to predict. This particular system could bring another good shot of late season snow, just a dusting, or even some rain/snow, depending on its track and the type of moisture it taps into as it nears the area. Some models show the system phasing with a subtropical moisture tap, which would raise snow levels above lake level. The unsettled pattern looks to continue through next weekend.

The backcountry hosts excellent powder today and will likely have more to come throughout the week. Best enjoy the fruits of nature before they quickly vanish with the arrival of warmer temps.

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

6″ new snow

0530 temp. at 8450′ Incline Peak TH: 20 deg. / 15 deg. at 0700

10-12″ new snow

Backcountry obs.:

Last night’s storm delivered. 10-12″ of cold, new snow has completely reset the backcountry, transforming it into a pristine, white wonderland. Sensors overnight showed temps dropping throughout the storm and they continue to do so this morning.

Light to moderate winds accompanied the snowfall adding a subtle rippled texture to the snow surface on open areas and along the summit ridge, but snow remained soft and fluffy. Winds from the SW did increase in intensity around daybreak with plumes of wind blown snow lofting above adjacent ridge lines.

Antecedent crusts from the prolonged warm spell are not noticeable underfoot and can only be felt with solid pole plants through the new snow.

No widespread instability red flags were noted, ie whumphing, cracking, or unstable windslabs. I did trigger minor sluffing within the top few inches of the new snow that ran the length of steeper chutes.

On the descent, the snow is skiing cold and fairly fast. It’s a gem of a March powder day. Enjoy!