March came in like a lion with several continuous days of snow. January and February snows in the Carson Range and throughout the Sierra increased an already above-average snowpack for this time of the year to 179% in the Tahoe Basin and 169% in the Truckee Basin.
The welcome snow contrasts with the dry winters for the previous two winters. With climate change making ever hotter summers the Truckee River had low flows, Sierra reservoirs shrunk, and Lake Tahoe fell nearly a half-foot below its rim for 65 days last fall and early winter.
Atmospheric Rivers helped to build the snowpack
Rain and then snow powered first by an “atmospheric river” and then a parade of January snow storms pushed the snowpack to over 150% in the Tahoe and Truckee Basin. Storms at the beginning and end of February continued to push the snowpack up and March is continuing the trend. As I write this, it is snowing lightly in Reno. (Another possible atmospheric river arriving in a couple of days could bring rain to lower elevation snowpack with a threat of increasing localized flooding possible.)
From nearly a half foot below its rim, Lake Tahoe today stands over two feet higher. With such a large snowpack yet to melt, Tahoe is set to rise considerably more. Likewise, reservoirs on the Truckee River system have storage available as evidenced by the following table of current levels.
Plenty of storage capacity remains in Truckee River Reservoirs
|Reservoir Name||Storage in Acre-feet||Capacity in Acre-feet||Current Storage %||Remaining Storage in Acre-feet||Remaining Capacity (%)|
|Lake Tahoe |
Where will this winter snowpack end up? March appears set to add more to the precipitation already received. The next storm system forecast is for rain at lower elevations below 7,000 feet to start.
The NRCS reports that “[a]s of March 1 the Reno Airport has seen 38.3 inches of snowfall through March 1 which is nearly twice normal for the entire winter.” The Airport has seen at least 4.5″ of snow fall since then.
Still, the total amount of precipitation from the winters of 1982-83 and 2016-17 exceeds this winter’s precipitation – so far.
† By court decree, the dam at Tahoe City, CA at the outlet to the Truckee River can raise the level of Lake Tahoe 6.1 feet to elevation 6,229.1 feet AMSL.