Tahoe Backcountry Snow

0415 temp. at 6350′ in Carnelian Bay: 26.8 deg. & 98% RH

Trace new snow

0515 temp. at 7450′ Rose Knob TH: 27 deg.

Backcountry obs.:

Snow has consolidated considerably in the lower portions of the Tahoe backcountry over the past 48 hours making travel easier and turns buttery soft.

Little to no new snow had accumulated overnight on Rose Knob and low clouds and fog hung over the peaks along the NE corner of the lake. Winds were generally light. The snow surface on NE-S aspects between 7400′ and 8900′ was soft and cold across all aspects, but had wind effect in open areas and on SE – S aspects. The raging winds of last weekend’s storm scoured most SW aspects down to bare ground in some areas and left ridge tops icy and textured with large cornices hanging to the lee. Just beneath ridgelines, soft wind pillows, drifts, and waves exist, adding some spice and features to the first few turns of descents. Open areas have some light wind texture atop soft snow.

Despite cold temps. and cloudy skies since the end of the storm, the snow has thickened and lost its light, blower consistency in favor of a thicker, buttery – but still super fun – powder. Speed and wide turns suggested. My guess is that the combination of March solar energy and high winds slightly heated and ground down snow grains into a more compact surface.

If your goal is anything with a S. facing or solar aspect, today might be the last opportunity for soft snow before suncrusts take over. The feet of snow left in the wake of the weekend storm have improved coverage dramatically from summit to lake shore bringing mid winter coverage to all backcountry zones in the Basin. It took forever, but was worth the wait.

Weather and forecast thoughts:

Today will bring a mix of clouds and sun with slightly warmer temps bringing highs into the mid 30’s around the lake and upper 20’s to low 30’s in the backcountry. High RH values will continue to promote thicker powder, even in colder areas. A few light snow showers may develop during the afternoon and early evening hours, but little to no accumulation is expected. Mostly cloudy skies will prevail tonight with lows again dropping into the 20’s.

Tomorrow and Thurs. expect mostly cloudy skies with highs in the upper 30’s to low 40’s around the lake. Snow showers are possible both days with areas along the crest receiving the best chances for a dusting or light surface refresh. Lows will efficiently cool each night into the teens – 20’s for the backcountry, likely preserving the fresh snow on sheltered and N facing areas.

Skies clear out Fri. and Sat. with slightly warmer temps and drier air: low 40’s at lake level/30’s in the backcountry. Lows will cool well into the teens and 20’s.

The end of the weekend and early next week bring back chances for snow showers with decently cold temps on Mon., but nothing that looks that impressive. Peeking out into the Pacific beyond the weekend, no big storms appear on the horizon. Some models hint at a stretch of high pressure building in starting around the middle of next week.

For now, it’s open season in the backcountry.

0600 temp. at 6350′ in Carnelian Bay: 19.9 deg.

24 hr. new snow as of 0800: 24″

Total storm total since Thurs., 2/29 at 0800: 62″

Backcountry obs.:

Backcountry obs have been limited throughout the storm due to lack of power and being snowed in. However, I did head out again to the 7000′ high point between Tahoe Vista and Agate Bay this morning. It’s deep. Very deep. Breaking trail, I sank down to knee/thigh depth with each step. Snow is right side up, but the upper 2-3′ of the new snowpack is not consolidated and comprised of cold, fluffy powder.

Strong SW winds continue to rake the area. Some wind effect and pillows cover windward SW aspects, but the snow surface in these areas is still soft. Unstable wind slabs are surely large and easy to trigger in steeper avalanche terrain.

The incredibly deep powder made turning unnecessary on the descent–gentle steering would be more accurate. The snow could use a day of two to consolidate to improve skiing in the backcountry.

Forecast and weather thoughts:

This has been quite the storm. All the anticipation and excitement was largely warranted as forecast snow totals have verified. Personally, I made a forecast for snow total amounts at my house with a friend for 56″ from Thurs. at 0800 through Sun. at 0800 and landed at 62″, and the snow continues falling. Here’s a breakdown:

2/29: 0800-2000: 2.5″

2/29-3/1: 2000-0800: 7.5″

3/1: 0800-2000: 9″

3/1-3/2: 2000-0800: 19″

3/2: 0800-2000: 14″

3/2-3/3: 2000-0800: 10″

Beyond snow totals, the hype surrounding wind speeds and blizzard conditions was justified as well. Widespread power outrages affected the Tahoe Basin on Fri. night as wind gusts whipped snow laden trees and branches onto power lines and utility infrastructure. Roads over the major passes in the area closed as well. There is still no projected opening time for I-80 & NV 431 in N. Lake and CA 88 in S. Lake as of this writing. Impressively, the summit of Alpine Meadows recorded a 184 mph wind gust around 9:15pm on the evening of 3/1. It was around this time that many in N. Lake lost power.

Things are winding down this afternoon, with intense bands of snow showers intermixed with brief peaks of sunshine. Gusty winds are still creating occasional whiteouts as they send tree laden snow airborne. Expect highs today to reach the mid to upper 20’s around the lake and teens in the backcountry.

Tonight snow showers will continue with modest accumulations of anywhere from 3-12″ depending on elevation and proximity to the crest. Winds will still gust from time to time, but should begin trending downward.

Tomorrow brings partly sunny skies and break with a few scattered snow showers firing up, especially in the afternoon hours bringing light accumulations. Temps will modify a bit to reach freezing in Sierra communities, while the backcountry will remain cold. Tomorrow could be an incredible day…

More on the forecast tomorrow. Time to start digging out.

0430 temp. at 6350′ in Carnelian Bay: 29.5 deg. w/ moderate snow

24 hr. new snow: 10″ from 0800 2/29 – 0800 3/1

Backcountry obs.:

The storm wasn’t coming in terribly hard this morning, so I decided to head out to Incline Peak to have a look-see. At about 7000′, conditions on Mt. Rose Highway deteriorated quickly with heavy snowfall and whiteout conditions. It was 23 deg. at the turnout and had not yet been plowed. Drifts were building in the roadway, so I opted to turn around and tour from home.

First tour of the season from the house! A fairly dense and right side up 10-12″ of new snow had fallen in the backcountry above Carnelian this morning. Coverage in this area pre storm was a mixed bag of bare ground and lumpy, crusty snowpack 1-3′ deep. Because the area is generally a S aspect, open windward zones were bare ground until this morning. Needless to say, coverage is improving and the area provided some mellow powder turns.

Weather and forecast thoughts:

Up to this morning, snowfall totals so far were on the lower end of the forecast amounts. Snow came in consistently yesterday, but as graupel and small, icy flakes. Temps. flirted with freezing in the late afternoon, but rose again to 32.4 deg. through the evening as bands of snow raked the area.

Starting at dawn, snowfall character has changed from dense, graupely snow, to a flakier, fluffy heavy snowfall, and accumulations will likely reflect the change.

Today expect snow to pick up in intensity as the heart of the multi-day storm arrives this afternoon through Sat. AM. Temps. today may nudge freezing at the lake in the early-mid afternoon, but will quickly crash back into the 20’s this evening with the arrival of the cold front. Heavy snowfall will become more consistent and reach rates of 3″ per hour, possibly up to 5″ per hour during the evening and overnight hours. These rates will be sustained as the cold front and unstable cold core of the storm behind the front arrive into Tahoe.

The airmass behind the cold front traces its origin to the Bering Sea and has traveled SE across the Gulf of Alaska over the past week. This trajectory makes the air hitting the Sierra cold, unstable, and incredibly moisture rich. Add the extra orographic lift that the range provides and boom: feet and feet of snow for Tahoe. Praise!

Winds will also pick up again this afternoon, creating the much-advertised blizzard conditions. It’ll be a great Fri. night to sit back with a whiskey, beer (or both) in front of a cozy fire.

Tomorrow morning will start out with snow dumping (3-5″ per hour) that may ease just a bit for the afternoon. This is relative, however, as rates of 1-3″ per hour do still qualify as respectable to ‘dumping’. Temps will not get out of the 20’s around lake level and gusty winds will continue. Snow quality will improve on this end of the storm as snow/water ratios rise into the 15/1 to 18/1 neighborhood.

The storm continue Sat. PM and Sun. Snowfall will turn more showery on Sun. and Sun. night with cold temps. prevailing. More snow is possible later next week.

For now, it’s time to sit back and enjoy the storm we’ve been waiting for all season.