It’s no secret that it’s been a very stormy winter in the Tahoe Sierra. In fact, snowfall totals during the month of January set new records at Donner Pass, Tahoe City and most ski resorts. But the real story in winter 2017 is hydrologic. Nearly a dozen Pacific-bred Atmospheric Rivers have produced phenomenal amounts of precipitation in a short period of time.
If you look to the far right-hand side of the graph, you can see how much more snow fell this January at the Central Sierra Snow Laboratory near Donner Pass than the preceding 45 years’ worth of Januaries. The 237 inches of snow blew away the old Jan. record set at the Lab in 1982. It also easily beat the all-time monthly snowfall record there, measured during the “Miracle March” of 1992.
Carnelian Bay is definitely not the snowiest location in the Tahoe Basin, but it has has really piled up this winter in the "banana belt." Peak ridge wind gusts this February reached 199 mph! The strongest storms that crash into the Tahoe Sierra reach Category 3 Hurricane strength.
January's heavy snowfall set the stage for long power outages, extensive road closures and frequent avalanches.
Resort totals are impressive: Alpine Meadows & Squaw Valley report more than 47 feet so far. Mt. Rose, where its high elevation converts mild AR rain to snow, leads regional ski areas with nearly 54 feet. Snowpack base amounts at Tahoe Basin resorts range from 8 to 22 feet deep.
In 2015, many streams, rivers and reservoirs in Northern California were near record lows; today officials are releasing torrents of water to make room for the looming spring melt of the massive mountain snowpack. The current “snow water equivalent” (SWE) in the expansive Northern Sierra pack is approaching 6.5 feet. At this time the federal water master for Lake Tahoe is releasing 500 cubic feet-per-second out of Big Blue to make room for the coming melt.
In early December 2016, the outlet of Lake Tahoe was just dirt with a lake level below the natural rim. Since October 1, Tahoe has risen nearly 4 feet and is now at 6,226.81 feet above mean sea level. Approximately 139 billion gallons of water have been added to Big Blue so far this season. That’s enough to supply the average annual water consumption for 435,500 four-member households.
These piers were high and dry last year. Given that the snow water equivalent (SWE) of the Tahoe Basin snowpack is more than 230% of normal, it’s a foregone conclusion that the lake will rise to its maximum legal limit by this summer. It will be the first time since 2006.