A Scripps Center for Western Weather and Water Extremes report shows that more atmospheric rivers have made landfall over the U.S. West Coast in the first four months of Water Year 2021 compared to the previous period in 2020.
How is California’s snowpack measured? Why is it important? And how is our snowpack stacking up this winter, so far? NBC 7 meteorologist Crystal Egger breaks it all down.
Precipitation is below average in California for the current water year. Despite recent storms that increased the statewide Sierra Nevada snowpack to 70% of average to date, the state is experiencing its second consecutive below average year for rain and snow.
Recent storms have boosted California’s vital Sierra Nevada snowpack but not enough to fully compensate for a dry start to winter and residents should use water wisely, a state official said Wednesday after the season’s latest measurements.
Precipitation is below average in California for the current water year. Despite recent storms that increased the statewide Sierra Nevada snowpack to 70% of average to date, the state is experiencing its second consecutive below average year for rain and snow. The water year starts on October 1 and ends September 30.
The Department of Water Resources Feb. 3 conducted the second manual snow survey of the season at Phillips Station. The manual survey recorded 63 inches of snow depth and a snow water equivalent, or SWE, of 17 inches, which is 93% of average for that location, according to the DWR. The SWE measures the amount of water contained in the snowpack and is a key component of DWR’s water supply forecast.
“The recent blast of winter weather was a welcome sight, but it was not enough to offset this winter’s dry start,” said DWR Director Karla Nemeth. “While there is still a chance we will see additional storms in the coming weeks, the Department and other state agencies are preparing for the potential for a second consecutive year of dry conditions.”
Below normal precipitation is favored throughout most of the southern tier of the United States in late February to early March, according to the National Weather Service Climate Prediction Center. La Niña conditions remain over the Pacific Ocean.
Statewide snow survey measurements reflect those dry conditions. Measurements from DWR’s electronic snow survey stations indicate that statewide the snowpack’s SWE is 12.5 inches, or 70% of the February 3 average, and 45% of the April 1 average. April 1 is typically when California’s snowpack is the deepest and has the highest SWE.
“The recent atmospheric storms have brought rain and snow to the northern Sierra Nevada, but conditions are still well below normal,” said Goldy Herbon, San Diego County Water Authority senior resources specialist.
Following last year’s below average water year, northern California is now experiencing its second straight water year of below average precipitation.
How it started.
How it's going.Season-to-date snowfall through January 23 vs February 4.#CAwx #CAsnow ❄️☃️🏂🌨️ pic.twitter.com/UOvjEmxa5k
— NWS Sacramento (@NWSSacramento) February 4, 2021
Another source of the state’s water supply, the Colorado River Basin, isn’t faring much better. The water year 2021 precipitation at the end of January for the Colorado River Basin is 66% of normal, according to the U.S. Bureau of Reclamation.
Precipitation totals to date are behind historical averages for two of the main sources of San Diego County’s supply, with two months to go in the winter season but, a couple of atmospheric rivers can change that quickly.
“The San Diego region will have a plentiful and reliable source of water due to actions taken by the Water Authority and its 24 member agencies to diversify the water supply,” said Herbon. “Continuing efforts to expand supply sources, including desalination, water reuse, and recycling, will ensure that the water needs are met for the region’s 3.3 million people and its $245 billion economy.”
Fall 2020 was extremely dry, especially in the Sierra Nevada, and follows last year’s below-average snow and precipitation, according to the DWR. With only a couple months remaining in California’s traditional wet season, DWR officials say Californians should look at ways to reduce water use at home.
Statewide Sierra Nevada snowpack is 71% of average for February 4, 2021. Graphic: California Department of Water Resources
California’s water picture is heading in two different directions.
A major storm last week and a more modest system Tuesday continued to boost the Sierra Nevada snowpack, the source of one-third of the state’s water supply, in promising ways. But the Bay Area and most cities across Northern California remain stuck in one of the worst two-year rainfall deficits seen since the 1849 Gold Rush, increasing the risk of water restrictions and dry wildfire conditions locally next summer.
This updates a post from December on the likelihood of California entering a second dry year. Normally, a second dry year brings drought operations for California’s overall water system operations.
Today, it is even likelier that California is entering a multi-year drought.
Precipitation conditions have improved somewhat with a nice atmospheric river this last week, but remain 51% of average for this time of year for the Sacramento Valley. (San Joaquin and Tulare basins are 61% and 47% of historical seasonal average precipitation so far.) Snowpack has improved somewhat with very recent storms, but is about as scarce as the precipitation.
California’s increasingly volatile warming climate is making droughts more intense, and complicating water management. A just-launched commodity futures market for the state’s water provides a new tool for farmers, municipalities and other interested parties to ensure against water price shocks arising from drought-fueled shortages.
Taking a Wall Street approach to an essential natural resource has prompted both fear and hype. Will California experience a new Gold Rush in water? Will speculation boost the cost of water? Perhaps both the fear and the hype are unwarranted.
Mayors and county supervisors in towns along the Colorado River were already upset five months ago when the state water agency endorsed an investment company’s plan to take water from farmland near the river and sell it to a growing Phoenix suburb.
Now, they’re incensed that the agency, which initially suggested holding back a large portion of the water, changed its stance and will let the company sell most of the water to the town of Queen Creek.
The Southwest U.S. is mired in an ever-worsening drought, one that has left deer starving in Hawaii, turned parts of the Rio Grande into a wading pool, and set a record in Colorado for the most days of “exceptional drought.”
The Water News Network is San Diego County’s source for water news and information.
