San Diego is experiencing one of the driest Februaries it has had in nearly 170 years due to weather patterns that are sending most winter storms into the Pacific Northwest and Northern California rather than allowing them to drop south, says the National Weather Service.
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.”
Precipitation below normal
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.
— NWS Sacramento (@NWSSacramento) February 4, 2021
Colorado River Basin
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.
A drenching storm that brought California much-needed rain in what had been a dry winter wound down Friday after washing out Highway 1 near Big Sur, burying the Sierra Nevada in snow and causing muddy flows from slopes burned bare by wildfires.
The atmospheric river weather system that barreled ashore in Northern California early in the week rolled quickly through Southern California overnight and was moving east before dawn. Remnants unleashed occasional downpours and hail.
A study last week predicts that massive, often-devastating “hundred-year storms” may occur three times as often and be 20% more severe in the U.S. due to climate change. The researchers, in a paper published in the American Geophysical Union journal Earth’s Future, found that if greenhouse gas emissions continue to increase at a rapid rate, the continental U.S. would likely see such mega-storms every 33 years.
The occurrence of historic rainfall events, like the ones that caused Hurricane Harvey in 2017 and California’s Great Flood of 1862, are likely to increase faster than lower-magnitude events, which already happen about every decade, according to UCLA climate scientist Daniel Swain.
In some places, more than an inch of precipitation fell Friday in Northern California while other places, including Sacramento, saw only a fraction of that. Whatever came down in the first rains of the season were a mere drop in the bucket.
California’s wild weather swings, from pounding rain to drought and from fires to floods, are widely expected to worsen as the climate warms. A new study shows just how severe things might get, and it’s not pretty.
California spent 376 weeks in a drought, from December of 2011 until March of 2019. That’s the longest duration of drought we’ve ever seen here in the Golden State. Now a study by Scripps Institution of Oceanography suggests wet and dry extremes in California are likely the result of severe storms called Atmospheric Rivers.
Though the last couple of weekends have seen wet weather, it hasn’t been enough to keep up with the yearly average in time for summer in California. The Sierra Nevada snowpack, which is tested regularly by employees of the California Department of Water Resources, has yielded some grim results so far in 2020 in terms of snow-water equivalent.