California’s first snow survey of the 2020-21 season is happening Dec. 30 at the Phillips snow course in the Sierra Nevada.
The Department of Water Resources will conduct five of these surveys through May by plunging a long steel tube into the snow. This will measure the snow’s depth and give an estimate of its water content.
No ‘March Miracle’ for snow and rain in California, but the San Diego County Water Authority has diversified water supply sources to weather the boom-and-bust cycle of California winters.
March brought abundant precipitation throughout California, but not enough to offset a dry February. Most large urban water agencies in the state maintain a reliable water supply in wet and dry years.
No ‘March Miracle’ for snow and rain in California, but the San Diego County Water Authority has diversified water supply sources to weather the boom-and-bust cycle of California winters.
March brought abundant precipitation throughout California, but not enough to offset a dry February. Most large urban water agencies in the state maintain a reliable water supply in wet and dry years.
“California’s climate variability is why a water resilience portfolio is needed to provide a safe and plentiful water supply,” said Goldy Herbon, Water Authority senior water resources specialist. “Whether a wet or dry year, the Water Authority and its 24 member agencies have successfully diversified water sources to ensure a reliable supply to meet the needs of the region’s 3.3 million people.”
The supply sources include water from the Claude “Bud” Lewis Carlsbad Desalination Plant, where ten workers volunteered to live on-site to keep the water flowing during the coronavirus pandemic.
March was wetter than normal for much of the region.
Some interesting numbers from last month: Palm Springs recorded their 4th wettest March on record, with more rain than San Diego!
San Diego recorded it's highest and lowest March temperature on the same day – March 3! #cawx pic.twitter.com/g0aIW7sqEv
— NWS San Diego (@NWSSanDiego) April 4, 2020
Lindbergh Field has received 9.76 inches of rain – or 108% of normal – from October 1, 2019 – April 2, 2020. Many areas in the San Diego region received snow in March, including the Anza-Borrego Desert State Park.
Even with a lackluster winter, the state’s six largest reservoirs hold between 82% and 125% of their historical averages for April 1, according to the California Department of Water Resources. Lake Shasta is 98% of its historical average and is at 79% of capacity.
The Department of Water Resources April 1 conducted the fourth manual snow survey of 2020 at Phillips Station near Lake Tahoe. The manual survey recorded 43.5 inches of snow depth and a snow water equivalent (SWE) of 16.5 inches, which is 66% of the April average for this location.
The SWE measures the amount of water contained in the snowpack, which provides a more accurate forecast of spring runoff. Measurements from the 130 electronic snow sensors, scattered throughout the state, indicate that the statewide snowpack’s water equivalent is 15.2 inches, or 53% of the April average.
The natural-color satellite images above, acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on NASA’s Terra and Aqua satellites, show the area covered by snow in March 2020 compared to March 2017 (a record high year). Graphic: NASA/NASA JPL
“While today’s survey results show our snowpack is better off than it was just last month, they still underscore the need for widespread, wise use of our water supplies,” said DWR Director Karla Nemeth. “California’s climate continues to show extreme unpredictability, and February’s record dryness is a clear example of the extremes associated with climate change.”
On average, the snowpack supplies about 30% of California’s water needs as it melts in the spring and early summer, the state agency reported in news release.
#ICYMI DWR conducted the 4th Phillips Station snow survey of 2020. The manual survey recorded 43.5" of snow depth & a snow water equivalent of 16.5", which is 66% of avg. for this location.
Statewide, the Sierra snowpack is 53% of avg.
More here: https://t.co/LYJxIHicfC pic.twitter.com/8tRS9RrMFU
— CA – DWR (@CA_DWR) April 1, 2020
April showers may be more scarce than normal north of Point Conception in California, according to an outlook produced by the National Oceanic and Atmospheric Administration.
This area where the probability of precipitation is below normal includes virtually all of Northern California and the crucial northern Sierra Nevada, where the state’s largest reservoirs are located.
While snow cover has increased thanks to a series of March storms, the Northern Sierra 8-Station Index stands at 56% of normal for the season. As of March 24, another 29.25 inches would be needed to reach the season normal of 54.52 inches.
California mountains are blanketed in snow and much of the state has had plenty of rain in a remarkable March turnabout from the extremely dry first two months of the year.
The most recent statewide storm started during the weekend and, despite diminishing, snow snowfall and showers were still occurring here and there.
In the Sierra Nevada, Homewood Mountain Resort on the west shore of Lake Tahoe reported late Tuesday a storm total of 114 inches (289.5 centimeters) of snow at its summit and 74 inches (188 centimeters) at the base.
One storm does not make a “Miracle March” but what an impact the last few days have had on the Sierra snowpack.
Continuous snow at Lake Tahoe since Saturday morning has added 13% to the snowpack, according to Jeff Anderson, water supply specialist for the Natural Resources Conservation Service in Nevada.
“To gain back that amount this time of year is really hard,” Anderson told the Tribune.
After a wet and snowy start, California’s winter has gone bust. The 2019-2020 water year started off with robust precipitation after a series of storms in November and early December 2019.
But the new year has not been as bountiful. Dry conditions in January and February added little to the Sierra Nevada snowpack.
Left: 2019, Right: 2020. Sierra Nevada snowpack is below normal for this time of year, at about 58% statewide. Graphic: NASA/National Weather Service via NWS Sacramento
Due to California’s climatological variability, including periods of drought, the Water Authority and its 24 member agencies have diversified water supply sources. Those successful efforts ensure supply reliability for the region’s 3.3 million residents and its $245 billion regional economy.
“Based on current supply levels, the Water Authority and its 24 member agencies will meet anticipated demands through a combination of drought-resilient local and regional water resources,” said Goldy Herbon, Water Authority senior water resources specialist.
Herbon said the Claude “Bud” Lewis Carlsbad Desalination Plant, conserved agricultural water transfers, savings from canal lining projects and continued water-use efficiency measures are among the reasons the region’s water supply will meet demand.
The multi-decade water supply diversification plan, along with major infrastructure improvements and forward-thinking policies, also promote fiscal and environmental responsibility.
“A comparison of the snowpack across the Sierra-Cascade range over the past 6 years shows the true variability of a California wet season. While numbers are similar to the 2017-2018 winter, snow did extend into somewhat lower elevations back then.” NWS Sacramento, February 26, 2020
While rainfall totals have been closer to average in most of Northern California, downtown Sacramento and downtown San Francisco did not receive any precipitation in February, according to the National Weather Service. The last time San Francisco saw a dry February was in 1864, according to the NWS.
February 2020 was the driest on record for the northern Sierra (8-station index)! Observed precip was 0.2 inches compared to the average of 8.2 inches. Data courtesy of @CA_DWR #cawx #cawater pic.twitter.com/PJMD7u2Uuu
— NWS California-Nevada RFC (@NWSCNRFC) March 1, 2020
Southern California is faring better, with rainfall at 125% of the historical average at Lindbergh Field in San Diego.
Most major California reservoirs are at or above the historical averages for late-February.
The state’s largest six reservoirs currently hold between 92% (Oroville) and 132% (Melones) of their historical averages for February 26. Lake Shasta, California’s largest surface reservoir, is 107% of its historical average and sits at 78% of capacity, according to the California Department of Water Resources.
California’s largest six reservoirs hold between 92% and 132% of their historical averages for Feb. 27. Lake Shasta, California’s largest surface reservoir, is at 107% of its historical average and is at 78% of capacity. Graphic: California Department of Water Resources
The Department of Water Resources February 27 conducted the third manual snow survey of 2020 at Phillips Station. The manual survey recorded 29 inches of snow depth and a snow water equivalent of 11.5 inches, which is 47% of the March average for this location, according to a DWR news release. The snow water equivalent measures the amount of water contained in the snowpack, which provides a more accurate forecast of spring runoff.
“Right now, 2020 is on track to be a below-average year but we could still see large storms in March and April that will improve the current snowpack,” said Sean de Guzman, chief of DWR’s Snow Surveys and Water Supply Forecasting Section. “While periods of dry conditions are expected in California, climate change has made them more unpredictable and extreme which is why we must always use the water we have wisely.”
The seasonal outlook for March, April, and May sees below-normal chances for a wet period across California and the Southwest U.S. while most areas are favored to be warmer than usual. Graphic: National Weather Service Climate Prediction Center
Looking ahead, the National Weather Service Climate Prediction Center forecast favors above-normal temperatures and below-normal precipitation through May for most of California.
The National Weather Service Climate Prediction Center forecast favors above-normal temperatures and below normal precipitation through May for most of California. Graphic: National Weather Service Climate Prediction Center
California, as everyone knows, receives virtually all of its precipitation during a few fall and winter months and in 2019, some early rain and snow storms promised a bountiful water year.
This year, Mother Nature kept that promise in Southern California, where precipitation is running at or above the normal, but Northern California — far more important from a water supply standpoint — has been a different story.
The north has seen almost no precipitation since Christmas, the all-important Sierra snowpack is less than half of its average depth, and the region’s balmy, springlike weather shows no signs of ending.
Despite President Donald Trump’s highly publicized signing of a memo last week directing more water to San Joaquin Valley farmers, the Bureau of Reclamation’s initial allocations announced Tuesday more closely reflected the below-normal Sierra snowpack and scant winter rain.
Farmers in the Friant Division will receive 20% of their Central Valley Project contract allocation while South-of-Delta growers will get 15%, Reclamation officials said.
The state Department of Water Resources reports that as of Monday, the average snow water content in the Sierra was 41% of the April 1 average. Northern Sierra precipitation is about 51% of the seasonal average.
What a difference a year makes.
As the comparison of satellite images above shows, last year at this time California’s Sierra Nevada range was buried in snow. And even as recently as January of this year, snowpack was looking pretty good.
But since then, the jet stream has ferried storms north of California, causing the snowpack to shrivel — from about 150 percent of average last February down to just a little more than 50 percent now.
The Water News Network is San Diego County’s source for water news and information.
