Atmospheric River Dumps High Volumes of Snow, Bolsters Snow Pack


Fri. March 23rd, 2018 - by Jessica Donnel

CALIFORNIA - The atmospheric river, on which we previously reported, has arrived, and it has arrived in full force! According to SFGate, the system dumped several feet of snow to elevations above 8,000 feet and brought a slushy mix of rain and snow to lower elevations.

Snow plows faced an apparently indomitable plain of snow drifts that rose above the tops of trucks, and, according to the news source, the roads were still impassable mid-day yesterday. Ski resorts, including Squaw Valley and Alpine Ski resort, were forced to shutter their lifts by early afternoon due to high avalanche conditions.

This animation from NOAA's Earth System Research Laboratory shows an atmospheric river event in January 2017. Atmospheric rivers are relatively narrow regions in the atmosphere that are responsible for most of the horizontal transport of water vapor outside of the tropics.

Due to its origins in the Pacific Ocean, this storm was warmer than the typical winter storm, and carried greater quantities of moisture, which it dumped as rain at elevations where snow may normally fall. But, despite the immense rains at lower levels, above 8,000 feet, the moisture rich storm bore more snow than a normal, colder winter storm could, explained SFGate.

The National Weather Services out of Reno reported considerable snow at high elevations with five feet of snow at elevations above 8,500 feet in Sonora, Ebbetts, and Carson Pass; and three feet of snow at elevations of about 7,000 feet for Donner Pass and Echo Summit, according to the news source.

With a second, more typical storm set to pass through the Sierra tonight, March 23rd, how will California's at-risk snowpack hold up into spring? AndNowUKnow will keep you updated on any storm systems that may impact crop production or drought conditions.