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California rain tops 2021. Are we still in a drought?

The dusty hills of Griffith Park sprout in shades of green. In Pasadena, water rushes through arroyos that just weeks ago were crusted and dried out. And from the perfect vantage point downtown, the distant San Gabriel Mountains gleam with snowcaps.

After one of the driest years in recent memory, Los Angeles – and California – got off to a particularly wet start. The state received more rainfall in the last three months of 2021 than in the previous 12 months, the National Weather Service said.

Nationwide, 33.9 trillion gallons of water have fallen since the start of the water year, which lasts Oct. 1 through Sept. 30, to offset the wet winter months and spring runoff. This three-month tally has already exceeded the 12-month total for the previous water year of 33.6 trillion gallons. For comparison, Lake Tahoe holds about 40 trillion gallons.

“It’s been a great start to the water year,” said Cory Mueller, meteorologist with the Sacramento Weather Service. “Most areas have already seen what they saw in the last water year and then some, just in the three months we had.”

Map showing percentage of normal precipitation for the water year to date.

Evidence of the atmospheric fluxes that hit northern California this fall and winter can be seen in this precipitation map.

(Paul Duginski/Los Angeles Times)

But while all that moisture gave a much-needed boost to statewide drought conditions, Mueller and other experts stressed that California must sustain this wet trend to truly emerge from its dry spell. The 2021 water year was the driest in California in a century, and more than half of the state’s water years since 2000 have been dry or drought years.

“Not getting a salary for three months and then getting a normal paycheck doesn’t put you back in your bank account,” said Noah Diffenbaugh, a climate scientist at Stanford University.

The same applies to the drought in California.

“These [precipitation] The deficits have been so severe in so many parts of the state that it will take more than a normal year to overcome, and we don’t know how this year will ultimately play out,” Diffenbaugh said. “Nonetheless, it’s a very encouraging start.”

In fact, there have been some promising improvements.

The US Drought Monitor map — which has long indicated severe, extreme or exceptional drought conditions in most parts of California — looked a little less worrisome after the early storms.

According to a Times analysis from Nov. 30 to Dec. 28, large parts of the state — including Los Angeles and much of the Sierra Nevada — saw at least one improvement. Almost no areas remain in the exceptional drought category.

Recent rains “haven’t completely eliminated the drought,” said Brad Pugh, a National Oceanic and Atmospheric Administration meteorologist who helps manage the drought monitor map. “There are still long-term rainfall deficits that go back two years. But it certainly helped improve drought conditions.”

Much of the state is still in the “extreme” drought category.

But Pugh said some seasonal forecasts are shifting in a positive direction. In October, NOAA favored a drier-than-normal winter, a prediction that failed in December.

The agency’s most recent three-month precipitation forecast now shows “equal probabilities of below, near, or above normal precipitation” for much of Northern California this season, Pugh said, adding, “It’s a slightly wetter outlook.”

Maps show improvement in drought conditions in California at the end of the year.

Although the state continues to be affected by drought, December rains brought about a dramatic improvement in conditions.

(Paul Duginski/Los Angeles Times)

Somewhat wetter prospects are also a welcome change from the parched state. In 2021, record-breaking heat and drought contributed to a devastating wildfire season that burned more than 2.5 million acres and destroyed thousands of homes.

Conditions were so dire that state officials had to transport juvenile salmon from the Central Valley to the Pacific Ocean because of low river levels. Later, for the first time, regulators were forced to shut down a large hydroelectric power plant on Lake Oroville due to low water.

And Lake Mead — long considered the lifeline for water in the West — shrank to historic lows, leaving a bare “bathtub ring” around its perimeter as a testament to how bad things had gotten.

Recent storms gave the region’s reservoirs a boost, but most are still missing, said Bill Patzert, a retired climatologist at NASA’s Jet Propulsion Laboratory.

“Reservoirs, particularly Lakes Mead and Lake Powell, are very depleted, groundwater and aquifers have been dangerously pulled down, and SoCal is where most of that nice Pacific rain ended up,” Patzert said.

Lake Mead had reached about 34% of its capacity as of Tuesday, according to the US Bureau of Reclamation. Lake Oroville was about 39%.

In a year-end update, California Department of Water Resources officials said December’s storms offered a “glimmer of hope” but that more was needed “before we can be in a place where drought conditions are no longer a factor.”

The 2020-21 water years combined are considered the two driest years on California’s statewide rainfall record, surpassing even the historic dry years of 1976-77, the agency said.

“Even if we get soaked and snowed in the next three months, it won’t erase the effects of two decades of repeated, repeated — mostly repeated — rain and snow deficits,” Patzert said.

Notably, much of the precipitation since October 1 has fallen as snow, which is extremely valuable both as a water source and as a water storage system in the state. Snowpack that melts during the warm spring and summer months tends to provide an additional burst of water when precipitation stops and demand peaks.

Yosemite National Park experienced its snowiest December on record for more than 40 years, park officials said. The snowfall gauge at Tuolumne Meadows recorded 154 inches of fresh snow through December 29, beating the previous record of 143 inches set in 1996.

The UC Berkeley Central Sierra Snow Lab at Donner Pass also recorded its snowiest December on record, at 214 inches, or more than 17 feet, officials said.

The powder mountains also broke the lab’s 51-year October-December snowfall record of 260 inches, set in 1970, with 268 inches falling during that three-month stretch that year.

“Not bad for a very dry November and early December,” said station manager Andrew Schwartz.

Based on records dating back to 1895, November 2021 was the seventh warmest and eighth driest November in the United States on record, with 46 of the 48 contiguous states reporting below-average rainfall, according to NOAA. California, particularly Southern California, along with the rest of the Southwest, stood out among the country’s driest regions.

But by the end of December the humidity had improved significantly. Officials conducted the first snow survey of the season at Phillips Station near South Lake Tahoe and found that the month’s storms brought snow cover in the state’s mountains to about 160% of the average for this time of year.

Humidity was plentiful even in southern California. On December 30, at least nine daily rainfall records were broken in the Los Angeles area, including an 85-year-old record of 2.34 inches in downtown LA

But a “wet start to the year doesn’t mean this year will end above average when all is said and done,” said Sean de Guzman, head of snow surveys for the Department of Water Resources, in a statement to the survey.

Agency director Karla Nemeth added, “We need more storms and average temperatures this winter and spring and we can’t be sure they will come.”

“It’s important that we continue to do our part to save – we’re going to need that water this summer,” she said.

Much will depend on what the rest of the season has to offer. Whether January, February and March will be as humid as December will depend on factors such as La Niña conditions and offshore pressure systems, experts said.

A La Niña pattern is currently in place in the tropical Pacific and forecasters expect it to persist through the winter before transitioning to a neutral pattern this spring. The pattern typically results in a drier than normal Southwest winter, as was the case in 2021.

According to Patzert, 84% of La Niña years since 1950 in Los Angeles have been drier than average.

Also of concern is the warming of global temperatures caused by climate change. Warm precipitation falls as rain instead of snow and can even melt valuable snowpack, said Diffenbaugh, the Stanford climate scientist.

“The state of drought is pending,” Diffenbaugh said, and depends in part on “how many storms we get in the coming months, how warm they are, and how much precipitation and snow they deliver to which parts of the state.”

A year that could shed some light on what the coming months may bring is 2012, when California experienced above-average rain and snow in December. The remainder of that water year ended bone dry, leading to the first year of a drought that lasted through 2017, state officials said.

The near-term outlook favors below-average precipitation and above-average temperatures in the West through mid-January, according to NOAA.

While more storms are expected in Sacramento and some northern parts of the state this week, other areas, including Los Angeles, are poised to stay sunny and dry.

https://www.latimes.com/california/story/2022-01-05/california-rain-exceeds-2021-are-we-still-in-a-drought California rain tops 2021. Are we still in a drought?

Tom Vazquez

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