Californians tend to regard our droughts in seasonal and annual terms: The winter storms fill reservoirs with rain and mountains with snow, or they don’t, or sometimes, like this year, they do so in the spring. But a new study proposes a broader perspective in which recent years’ shifts from dry to wet to weird are just minor variations within a longer and more extraordinary period of widespread parching.
In the next 16-45 years, two-thirds of Western states may have to turn away from snowpack and find new tools to predict drought.
And by the late century, scientists estimate that area will grow to four-fifths of the western United States, according to a new paper in Nature Climate Change.
“When the temperature warms, the phase of the precipitation is likely to change from snow to rain. So less snowpack is something that’s pretty likely,” said lead author Ben Livneh, an assistant professor of civil, environmental and architectural engineering at the University of Colorado Boulder.
Farmers in parts of the western United States who rely on snowmelt to help irrigate their crops will be among the hardest hit in the world by climate change, a new study reveals.
Record-breaking April rains eliminated all drought and abnormal dryness from Southern California and up the Central Coast through Monterey County, but drought has worsened in northwestern California, the U.S. Drought Monitor said Thursday.
Spring storms that included five consecutive days of soaking rain last week knocked out drought conditions in Southern California, according to this week’s U.S. Drought Monitor report.
A two-decade-long dry spell that has parched much of the western United States is turning into one of the deepest megadroughts in the region in more than 1,200 years, a new study found.
And about half of this historic drought can be blamed on man-made global warming, according to a study in Thursday’s journal Science.
Scientists looked at a nine-state area from Oregon and Wyoming down through California and New Mexico, plus a sliver of southwestern Montana and parts of northern Mexico. They used thousands of tree rings to compare a drought that started in 2000 and is still going — despite a wet 2019 — to four past megadroughts since the year 800.
The mighty Rio Grande is looking less mighty as U.S. forecasters predict spring flows will be less than half of average — or worse — and that signals potential trouble for the already stressed waterway.
To hear that the weather is producing average results prompts thoughts of a metronome, plain brown wrappers and the smell of vanilla. But that certainly is not how Los Angeles’s rain intake for the water year has reached its historical average.
U.S. Drought Monitor data released Thursday show that less of California is abnormally dry, and more of the state is drought-free.
The improvement is mostly in Southern California and along the Central Coast, while data for Northern California show little change.
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
