Tahoe Backcountry Snow

0400 temp. at 6350′ in Carnelian Bay: 22.6 deg. w/ 73% RH and 15.3 deg. dew point

0515 temp. at 8650′ Mt. Rose backcountry TH: 10 deg.

Backcountry obs.:

It’s not often that storms deliver a foot of Utah-like blower pow to Tahoe. It’s even rarer for a storm to deliver almost entirely on the east side of the lake, with nearly nothing on the crest. The storm over the past weekend delivered both rarities.

On Sun morning (1/26) the Rose backcountry hosted anywhere from 10-14″ of light, dry powder as light snow continued falling throughout the morning with generally light winds. Near and below treeline, delicate, blower powder adorned each tree branch and smoothed out every abuse and imperfection in the haggard, weeks old snow surface. Despite the quantity of new snow, the incredibly light density skied as though nearly nothing rested atop. What deceit!

Beware: sharks lurk! Stumps and rocks previously visible above the snow, are now buried beneath a foot of pixie dust that behaves more like thick surface fog from a smoke machine on a dance floor than a riding surface.

As such, the new snow bonded poorly to old surfaces creating plentiful sluffing in steep terrain, but not enough to entrain a skier or bury a person.

By Monday morning, continued cold temps kept the snow light, fluffy and barely notable underfoot below treeline. Near treeline, N-E aspects had subtle wind effect and some very light rime atop the new snow, adding a bit more density underfoot between skier and hard surfaces beneath. Above treeline zones on N-E aspects were largely wind scoured down to cold, hard crusts.

Weather and forecast thoughts:

The storm that dropped the surprise amount of powder slowly exited the region early this morning (1/27) leaving cool temps, clear skies, and building inversions in its wake. Cold temps should prevail in the backcountry throughout the week.

By next weekend, models now agree on a pattern change bringing Pacific moisture back to the Sierra starting over the weekend and possibly persisting into the following week.

Details are still hazy regarding timing, intensity, and snow levels. However, at this point the first round looks relatively mild with snow levels at or above lake level, at least initially.

As the pattern evolves, cooler air may filter into subsequent disturbances later next week, bringing snow levels down.

Uncertainty is still high regarding details, but for now, it looks like the atmosphere may indeed crack a cold one to commemorate the end of dry January.

0400 temp. at 6350′ in Carnelian Bay: 29.1 deg / 12.9 deg dew point / 49% RH

0515 temp. at 8650′ Mt. Rose backcountry TH: 22 deg.

Backcountry obs.:

Dry and stable conditions continued this morning in the Rose backcountry. And it’s not just dry, but anomalously so! This morning at 3:30am, the sensor atop Slide Mountain registered a dew point of -39 deg F. That comes out to a relative humidity of just 4%! Aside from cracking everyone’s lips and cuticles, it’s also having an impact on the snow pack by sublimating out moisture, leading to facet formation on the surface. In layman’s terms: recycled pow.

Recycled pow continues to be widespread throughout shady, tree protected NW-NE aspects in the backcountry above 8000′, while crusts exist on any sun-exposed terrain (E-S-W aspects). Above treeline windboard, sastrugi, and bullet proof ice reign. While cold, protected aspects still host pow, solar aspects with coverage are now beginning to develop soft, mid-winter corn, if you hit it at just the right time: late morning-mid afternoon.

If you know where to look, there’s still fun snow out there despite no new snow in nearly 3 weeks.

Weather and forecast thoughts:

For the first time in weeks, new snow is actually in the forecast for the coming weekend (1/25-26). And with a generous scoop of good fortune, enough may fall to provide a refresh. Beyond the weekend, seasonal temps and dry conditions return as the dominant E. Pacific ridge of high pressure rebuilds for the coming work week (1/27-31). Mixed signals continue to appear in models for the first weekend in February and beyond.

Conditions in the backcountry for today and tomorrow will remain benign with mild afternoons into the upper 30s and low 40s under sunny skies. Lows tonight will dip back to the 20s and 30s, depending on location. High elevation peaks and ridges will stay considerably warmer than depressions as inversions return, especially Thurs. night. Fri (1/24) will be mostly sunny and mild with light winds, increasing by the afternoon heralding the arrival of the coming weekend system.

Late Fri – Sun a system moves in that could produce a few inches of snow. Models depict a modest cut off low developing over the Eastern Sierra on Saturday, then meandering out towards the coast and back inland on late Sunday. The moisture-starved system could produce a few inches of cold, dry powder over the weekend, mainly favoring areas from Tahoe southward into Mono County. The bigger story will be the cold temps and brisk NE winds. Highs in the backcountry on Sat will struggle to reach 20 deg with low 20s at best on Sun afternoon. Brisk NE winds will blow both days, chilling things even further. By the time the system slinks its way out to the east, expect 1-4″ of new snow in the Tahoe backcountry.

Models show a return of the blocking E Pacific ridge next week, bringing another helping of dry, calm conditions and seasonably cool temps. Hopefully the dry airmass preserves whatever new snow falls over the weekend. Expect daily inversions to redevelop across the mountains with ridges and peaks staying 5-10 deg warmer than valley locations each night.

Models are picking up some noise on the horizon as Jan bleeds into Feb, but confidence remains low. Until the blocking pattern in the E Pacific shifts or dissipates dramatically, chances of getting any meaningful snowfall will remain remote.

For now, it’s time to get amped at the possibility of a few inches of blower dust on crust!