As of January 20, the Sierra snowpack state-wide was at 240 percent of the average for this time of year. The South Sierra stations, located between the San Joaquin and Mono counties through to Kern county, reported snowpacks at 283 percent of the January 20 average.
The Sierra Nevada snowpack usually peaks around April 1. Currently, state-wide, the snowpack is at 126 percent of the average for April 1, with the South Sierras in particular at 149 percent.
“The snowpack in California is now 240 percent of average for this date and is at 126 percent of average for the April 1 measurement. We are now within 4” of our normal seasonal snowfall at the snow lab of 360" (current is 356")," Andrew Schwartz, the lead scientist and manager at the Central Sierra Snow Laboratory, UC Berkeley, told Newsweek.
The Sierra Nevada mountain range stretches about 400 miles from north to south, between the Central Valley of California and the Great Basin. The amounts of snow falling in the higher elevations of the Sierras come as a result of several powerful atmospheric river storm systems hitting the West Coast, which led to huge rainfall and flooding at lower ground.
“Updated total precipitation map for California for a period of 22 days stretching from December 26 to January 17. The AVERAGE over the ENTIRE STATE in that time frame was 11.47 inches, with several locations in central California setting 3-week records,” tweeted the National Weather Service’s NWS Weather Prediction Center on January 19.
This larger snowpack could be a boon for the state, helping to combat California’s drought in the coming months.
“There is a tremendous amount of snow this year, so that’s very encouraging,” Donald Bader, the Lake Shasta area manager for the U.S. Bureau of Reclamation, previously told Newsweek. “That will come down later in the spring when it starts warming up, so we can anticipate that and add that to our [reservoir] storage volumes because we know we’ve got that extra storage sitting up there in the mountains.”
This snow will eventually melt, and run down from the mountains into reservoirs and at lower elevations. Sierra Nevada snowmelt supplies about 30 percent of California’s water requirements throughout the year, and the fact that the snowpack is now over the average yearly peak is very encouraging for the water supplies for the coming year.
These effects may help to replenish water levels not only in California reservoirs like Lake Shasta and Lake Oroville in Butte County, both in the northern part of the state, but also as far as the Colorado River basin, even helping Lake Powell in Utah and Arizona.
“We may see increased inflows to Lake Powell compared to recent years if we continue to get widespread increases across the western U.S. However, we won’t know the extent of level increases until later in the spring. At this point, it’s still too early to speculate,” Schwartz said.
While the large levels of snow will certainly help California alleviate its drought, alongside the large amounts of water having fallen as rain this month of January, the state still requires a large amount of rain to fully replenish the groundwater supplies.
“Surface water levels are only part of the picture—groundwater levels will likely still remain chronically low, because (rain or no rain) we deplete more groundwater than is replenished,” Aakash Ahamed, a hydrologist and co-founder of the Water Data Lab, previously told Newsweek.
Additionally, if the temperatures in the Sierras increase too fast, the snow will melt too rapidly to properly be absorbed into the ground, instead running straight into the ocean, Jacob Petersen-Perlman, a water resources geography expert and assistant professor at East Carolina University, previously told Newsweek.
Despite numerous challenges still ahead, the recent rains have made a massive impact on the drought status of California so far. As of January 3, the U.S. Drought Monitor showed that 27.10 percent of the state was in “extreme drought,” and 2.07 percent was drought-free or “abnormally dry” instead. January 17 data shows that, 0 percent of the state is under “extreme drought,” 42.84 percent was in “severe drought,” 49.28 is experiencing “moderate drought,” while 7.24 percent was “abnormally dry.”
For the first time in a long time, 0.64 percent of the state is considered free of any drought or drought-like conditions, in a small section of Del Norte County on the Oregon border.
The snowy and icy conditions in the Sierras have had some negative impacts such as posing a risk for motorists, with slippery roads and whiteout conditions making travel difficult.
Additionally, the snowpack melting may cause issues depending on how rapidly it occurs.
“There isn’t really too much risk with an above average snowpack unless we get a sudden melt event, which can cause flooding,” Schwartz previously told Newsweek.
“We do have some risks associated with increasingly snowy conditions, such as increased avalanche risk, strain on structures and equipment, and problems with travel during the storms. One of the largest issues that we see in above average years around the Donner Summit area is propane leaks that develop from tanks buried under the heavy snow. It has resulted in explosions in the past.”
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