No one really knows how much snow fell on the infamous Donner Party when the pioneers were trapped atop the Sierra Nevada for months and dozens died near Lake Tahoe in the winter of 1846-47.
But this season has now etched its way into the history books as the second snowiest in the 77 years of record-keeping at the Central Sierra Snow Lab — more than 56.4 feet (677 inches, 17.2 meters) with no end in sight.
NOAA’s U.S. Spring Outlook indicates the abnormally wet winter will further improve drought across much of the western U.S. as the snowpack melts in the coming months. Winter precipitation, combined with recent storms, wiped out exceptional and extreme drought in California for the first time since 2020, and is expected to further improve drought conditions this spring.
Significant flooding in the western U.S., especially in California, followed another series of strong Pacific storms that battered the region in March, and piled on to an already historic snowpack.
A series of atmospheric river events with heavy rain and snow have caused California water regulators to open flood gates on water storage facilities, but the uncertainty of when Mother Nature’s faucet will shut off has experts weighing the advantages and disadvantages of letting the precious resource run free.
With recent storm systems that swept through the west, California has seen more precipitation this year than normal, bringing the water supply stored in reservoirs — both locally and across the state — up from historic lows to levels that are some of the highest in years.
And with drought conditions having improved in much of California, experts say that the amount of water captured from this year’s particularly wet winter could help ease the impact of hotter, drier weather in San Diego, as the state recovers its depleted water supplies.
Two winters’ worth of snow has already fallen in the Sierra Nevada since Christmas, pulling California from the depths of extreme drought into one of its wettest winters in memory.
But as a series of tropical storms slams the state, that bounty has become a flood risk as warm rains fall on the state’s record snowpack, causing rapid melting and jeopardizing Central Valley towns still soggy from January’s deluges.
The winter of 2022-23 will go into the meteorological record books for one of the heaviest – if not, the heaviest – precipitation ever experienced in California.
California has been buffeted for more than two months by a seemingly nonstop series of storms rolling in from the Pacific, soaking virtually every corner of the state. Their most unusual aspect has been the huge snowfall in Southern California mountains, where hundreds of people remain trapped in resort communities.
The snow water equivalent of California’s snowpack is 190% of average for March 3, 2023. After three years of drought, the bountiful winter is good news, but a drier future demands more conservation and innovative solutions for water supply in the Southwestern U.S.
The Department of Water Resources on March 3, conducted the third snow survey of the season at Phillips Station in the Sierra Nevada. The manual survey recorded 116.5 inches of snow depth and a snow water equivalent of 41.5 inches, which is 177% of average for the location on March 3. Snow water equivalent measures the amount of water contained in the snowpack and is a key component of DWR’s water supply forecast.
DWR’s electronic readings from 130 snow sensors placed throughout the state indicate the statewide snowpack’s snow water equivalent is 44.7 inches, or 190% of average for this date.
“Thankfully the recent storms combined with the January atmospheric rivers have contributed to an above-average snowpack that will help fill some of the state’s reservoirs and maximize groundwater recharge efforts. But the benefits vary by region, and the Northern Sierra, home to the state’s largest reservoir Lake Shasta, is lagging behind the rest of the Sierra,” DWR Director Karla Nemeth said. “It will also take more than one good year to begin recovery of the state’s groundwater basins.”
Although the statewide snowpack is currently just behind the record snow year of 1982-83, the snowpack varies considerably by region. The Southern Sierra snowpack is currently 209 percent of its April 1 average and the Central Sierra is at 175 percent of its April 1 average. However, the critical Northern Sierra, where the state’s largest surface water reservoirs are located, is at 136 percent of its April 1 average. With one month of the traditional wet season remaining, DWR is providing updated runoff forecasts to water managers and is closely monitoring spring runoff scenarios and river flows to ensure the most water supply benefits from this year’s snowpack while balancing the need for flood control.
“The recent storms over the past week broke a month-long dry spell in a dramatic way,” said DWR’s Snow Surveys and Water Supply Forecasting Unit Manager Sean de Guzman. “We are hopeful that we will see more cold storms to add to our snowpack for the next month and help set up a long, slow melt period into spring.”
“The results of today’s snow survey is good news for the state’s water supply, especially for those parts of the state that rely on snowmelt as their primary source of water,” said San Diego County Water Authority Water Resources Manager Jeff Stephenson. “The above average snowpack levels come after three consecutive years of drought that resulted in below normal water levels at the state’s major reservoirs. For the San Diego region, the recent local storms allow residents and businesses to turn off sprinklers and irrigation for at least several weeks, if not longer. This allows the region to keep more water in local reservoirs for use later in the year.”
Rebates, classes and more free services to #SaveOurWater for residents and businesses are available in San Diego County. Programs and rebates information here: https://t.co/1LnJNWI4Ow @saveourwater @bewaterwiseh2o #WaterSmartSD #cawater #CAwx
— San Diego County Water Authority (@sdcwa) March 3, 2023
“Despite the recent wet weather and the region’s diverse water supply portfolio, the long-term forecast of a hotter, drier climate, for the Southwest U.S., means that water use efficiency remains a key part of saving our most precious resource, in wet or dry years,” added Stephenson.
Stephenson said that there are rebates and other free services available to residents and businesses of San Diego County that can help conserve water and save money.
“Recent storms combined with the Jan. atmospheric rivers have contributed to an above-average snowpack. But the benefits vary by region, and… it will also take more than one good year to begin recovery of the state’s groundwater basins.” – DWR Director Karla Nemeth pic.twitter.com/1yhJ4cm6F1
— CA – DWR (@CA_DWR) March 3, 2023
To ensure water supply managers have the most current forecasts of snowpack runoff, DWR is utilizing the best available technology to collect the most accurate snow measurements. DWR’s Snow Surveys and Water Supply Forecasting Unit is utilizing Airborne Snow Observatory (ASO) surveys across 12 of California’s major snow-producing watersheds to collect data on the snowpack’s density, depth, reflectiveness, and other factors down to a 3-meter resolution. These flights, which utilize LiDAR and imaging spectrometer technology, provide DWR with more information on water content than ever before, which is then fed into advanced physically based and spatially explicit models to generate the most accurate water supply runoff forecasts possible. These forecasts are used to develop the Bulletin 120 for forecasted spring run-off to determine water allocation and stream flows for the benefit of the environment.
Did you miss today's third snow survey of the season at Phillips Station? Read more about California’s snowpack showing huge gains from recent storms and what that means for the state at https://t.co/JW2fBrM4cR#california #snow #water #cawater #SnowSurvey2023 pic.twitter.com/1JbdS9iduV
— CA – DWR (@CA_DWR) March 3, 2023
While winter storms have helped the snowpack and reservoirs, groundwater basins are much slower to recover. Many rural areas are still experiencing water supply challenges, especially communities that rely on groundwater supplies which have been depleted due to prolonged drought. It will take more than a single wet year for groundwater levels to substantially improve at a statewide scale. Drought impacts also vary by location and drought recovery will need to be evaluated on a regional scale and will depend on local water supply conditions.
On February 13, Governor Newsom issued an Executive Order directing state agencies to review and provide recommendations on the state’s drought response actions by the end of April, including the possibility of terminating specific emergency provisions that are no longer needed, once there is greater clarity about the hydrologic conditions this year.
Californians should still continue to use water wisely so that we can have a thriving economy, community, and environment. DWR encourages Californians to visit SaveOurWater.com for water saving tips and information as more swings between wet and dry conditions will continue in the future.
DWR conducts five media-oriented snow surveys at Phillips Station each winter near the first of each month, January through April and, if necessary, May. The next survey is tentatively scheduled for April 3.
California was hit Monday with yet another winter storm, adding to what has become an unusually cold and wet season that some experts say has the chance to become one of the snowiest on record if conditions continue.
The new winter storm is forecast to bring more rain and snow across the state through Wednesday, though forecasters say it isn’t expected to be as exceptional as the previous system, which brought snowfall to unusually low elevations almost statewide.
A series of winter storms will work together to usher in some of the coldest and windiest conditions of the season across California. These winds will be accompanied by waves of atmospheric moisture that will crash into Northern California from Wednesday to Friday morning.
Widespread rain showers will impact most of the Bay Area on Wednesday through Friday, while periods of snow showers will be possible farther inland — including the Sierra Nevada and some foothills near the coast. These winter storms will also hoist thunderstorms onto the coastline, raising the chances for small hail and ice pellets in areas along Highways 101 and 1.
Extreme weather hammered California through the first weeks of the year – but also offered a badly needed reprieve. The deep snow dumped on the Sierra Nevada during a series of strong storms left the state with a robust water savings account of sorts.
As the weather warms over the spring and summer months, the melting snow fills rivers, streams and reservoirs long after California’s rainy season has ended. Considered one of its most important reservoirs, the snowpack provides roughly a third of California’s water supply.
The Water News Network is San Diego County’s source for water news and information.
