<\/p>\n
La Ni\u00f1a winters are typically drier in the Southwest.<\/p>\n
(Paul Duginski \/ Los Angeles Times)<\/p>\n
Out of 25 La Ni\u00f1as since 1954, 15 have brought drier-than-normal conditions to California. <\/p>\n
But La Ni\u00f1a \u201cdoesn\u2019t always mean drought,\u201d said meteorologist Jan Null, an adjunct professor at San Jose State University.<\/p>\n
In fact, out of the seven La Ni\u00f1as seen over the last 15 years, three were whoppers when it came to rain.<\/p>\n
Powerful storms pounded California throughout 2010-11, building a snowpack so epic<\/a> that ski resorts actually complained<\/a>. <\/p>\n The 2016-17 La Ni\u00f1a season brought downtown L.A. 134% of its average annual rainfall. It was the second-wettest season <\/a>in terms of statewide precipitation and single-handedly ended California\u2019s punishing five-year drought.<\/p>\n Water flows over the damaged main spillway at Lake Oroville and into the Feather River on Feb. 11, 2017. <\/p>\n (Brian van der Brug \/ Los Angeles Times)<\/p>\n So much rain fell that season that California\u2019s second-largest reservoir, Lake Oroville, spilled over its brim. Mass evacuations were ordered amid fears a key retaining wall<\/a> could collapse, sending floodwaters rushing into communities below \u2014 a tragedy that was ultimately averted. <\/p>\n But in San Jos\u00e9, floodwaters did pour<\/a> out of Coyote Creek and into many homes. The snowpack was so heavy that skiers were sailing down Sierra slopes in bikini tops<\/a> and underwear in June. <\/p>\n The 2022-23 La Ni\u00f1a season was yet another drought-buster, marking the end of California\u2019s driest three-year period<\/a> on record. <\/p>\n Heavy rains triggered a landslide near apartment buildings in San Clemente in March 2023.<\/p>\n (Allen J. Schaben \/ Los Angeles Times)<\/p>\n Even so, Californians who lived through the 1980s and \u201990s tend to think in absolutes about La Ni\u00f1a and its better-known counterpart, El Ni\u00f1o \u2014 with the former seemingly the \u201cdemon diva of drought<\/a>\u201d and the latter a herald of epic rains and floods.<\/p>\n The truth is La Ni\u00f1a and El Ni\u00f1o are by no means the only predictor of climate patterns going into California\u2019s autumn-and-winter rain-and-snow season.<\/p>\n \u201cEl Ni\u00f1o\/La Ni\u00f1a predictions are a bit like poker, where you may have a good hand, but when you draw the last card, you don\u2019t get what you\u2019re looking for,\u201d said Marty Ralph, director of the Center for Western Weather and Water Extremes at the Scripps Institution of Oceanography at UC San Diego.<\/p>\n During El Ni\u00f1o, sea surface temperatures rise in the central and eastern Pacific. The jet stream moves south, pointing a potential fire hose of moisture straight at California, especially in the southern section of the state.<\/p>\n This map shows the typical effects of an El Ni\u00f1o pattern on winter in North America.<\/p>\n (Paul Duginski \/ Los Angeles Times)<\/p>\n \u201cWe saw in the \u201980s and \u201990s really good correspondence between the El Ni\u00f1o\/La Ni\u00f1a behaviors in Southern California precipitation anomalies \u2014 wet El Ni\u00f1os down here, and dry La Ni\u00f1as,\u201d Ralph said. \u201cBut interestingly, when we switched over to the 21st century, somehow, something changed.\u201d<\/p>\n Some El Ni\u00f1os have been out of character for California, too. The driest water year<\/a> in downtown Los Angeles\u2019 recorded history, 2006-07, occurred during an El Ni\u00f1o. Then there was the \u201cGodzilla<\/a>\u201d El Ni\u00f1o ahead of the 2015-16 water year that led to a below-average winter in Southern California and either average or above-average precipitation<\/a> in Northern California despite its enormous strength in the ocean. <\/p>\n Ralph and his colleagues tried to figure out why certain La Ni\u00f1a and El Ni\u00f1o water years were, as they put it, \u201cheretical\u201d \u2014 acting with \u201cradical deviation\u201d to what they would expect. <\/p>\n What they found was that La Ni\u00f1a and El Ni\u00f1o do likely influence certain storms that hit California \u2014 but only the typical seasonal variety that originate from Alaska or north of Hawaii, Ralph said. <\/p>\n What La Ni\u00f1a and El Ni\u00f1o don\u2019t affect, however, are \u201catmospheric rivers,\u201d which can carry tremendous amounts of rain and snow to California from the tropics, Ralph said. The findings were reported in February in the journal Climate Dynamics<\/a>. <\/p>\n Homes in San Jos\u00e9 were flooded during epic rains in early 2017.<\/p>\n (David Butow \/ For The Times)<\/p>\n Each atmospheric river can carry a boatload of water. Just four to five would result in an average rainy season for Southern California, Ralph said. Atmospheric rivers fueled the powerful storms that hit California this October<\/a> and November<\/a>. <\/p>\n An average atmospheric river transports more than double the flow of the Amazon River, according to the American Meteorological Society. <\/p>\n Atmospheric rivers, on average, account for up to 65% of the annual precipitation in Northern California. But there can be wild swings year to year, with atmospheric rivers contributing anywhere from 5% to 71% of Southern California\u2019s annual precipitation, the report said. <\/p>\n Also meriting further study is whether climate change is upending the old rules of La Ni\u00f1a and El Ni\u00f1o, since atmospheric rivers \u201care projected to be increasingly greater contributors to total annual precipitation, boosting extreme precipitation and increasing the year-to-year variability of Western hydroclimate in the warming future,\u201d the researchers wrote. <\/p>\n A classic setup for a \u201cpineapple express\u201d atmospheric river that taps moisture from the tropics.<\/p>\n (Paul Duginski \/ Los Angeles Times)<\/p>\n Officials have long warned that continued climate change could whipsaw California between precipitation extremes, with the state trending toward aridity, interspersed with exceptionally wet years.<\/p>\n \u201cLa Ni\u00f1a and El Ni\u00f1o are not the only player in the game,\u201d Null said. \u201cI think we need to add an appendix to that playbook. Part of that is climate change-driven. … There\u2019s climate change in the DNA of every weather event that\u2019s going on.\u201d <\/p>\n California has seen unusually wet storms this autumn because of a persistent low-pressure system off the West Coast that stretched farther south than is typical for October and November. That system was able to tap into unusually potent precipitation in the deep tropics and dispatch atmospheric river storms to the state, said Jon Gottschalck, chief of the National Oceanic and Atmospheric Administration Climate Prediction Center\u2019s Operational Prediction Branch. <\/p>\n Santa Barbara Airport has so far recorded its wettest start to the water year with 9.91 inches of rain, blowing past the previous record of 7 inches, according to<\/a> the National Weather Service office in Oxnard. <\/p>\n Since Oct. 1, UCLA has netted 8.75 inches and downtown Los Angeles 6.94 inches \u2014 about half their average yearly totals. <\/p>\n Even famously and formidably dry Death Valley National Park saw its wettest November on record, recording 1.76 inches of rain, surpassing the previous high-water mark of 1.7 inches in 1923, according to Chris Outler, a meteorologist with the National Weather Service office in Las Vegas. <\/p>\n Las Vegas recorded its second-wettest September-October-November period this year, with 2.91 inches of rain. <\/p>\n The rainfall across Southern California was relatively heavy for this time of year, enough to dramatically tamp down wildfire risk, but not so heavy as to cause catastrophic landslides. <\/p>\n \u201cIt\u2019s sort of a Goldilocks AR,\u201d Ralph said. <\/p>\n But what hasn\u2019t been ideal is how warm California has been. Ski resorts have been lamenting how the recent storms haven\u2019t produced much snow. A healthy snowpack is key to<\/a> California\u2019s annual water supply, building up a seasonal icy reservoir in the mountains that no man-made lakes could ever hope to match. <\/p>\n The same low-pressure system off the coast that helped fuel recent atmospheric rivers is also pushing in air from areas to California\u2019s west and southwest. That\u2019s warmer than when air plunges into California from Alaska or Canada.<\/p>\n As a result, November\u2019s temperatures have been \u201cincredibly above normal\u201d across the entire West, Gottschalck said. \u201cThere has been precipitation in Northern California … but it\u2019s been too warm,\u201d he said.<\/p>\n Snow-making machines are used on the slopes in Big Bear on Thursday. Low snow levels have delayed the opening of Southern California ski resorts. <\/p>\n (Gina Ferazzi \/ Los Angeles Times)<\/p>\n The early wet start to California\u2019s rain-and-snow season also doesn\u2019t necessarily mean \u201cit\u2019s going to be wet through the whole winter,\u201d Gottschalck said. \u201cIt doesn\u2019t work that way.\u201d<\/p>\n Just look at the 2021-22 season \u2014 a La Ni\u00f1a. October 2021<\/a> was the fourth-wettest October in California history, courtesy of a Category 5 atmospheric river, the most destructive. But the following January-through-April was the driest such period on record in California. By April 2022, California\u2019s snowpack was only 38% of its typical average<\/a>. <\/p>\n There are no major rain or snowstorms in the forecast throughout early December in California as of now.<\/p>\n \u201cRecent history has shown us that anything can happen during a California winter,\u201d said Karla Nemeth, director of the California Department of Water Resources.<\/p>\n","protected":false},"excerpt":{"rendered":"Californians can be excused for being confused about the weather forecast. Scientists in October said La Ni\u00f1a had…\n","protected":false},"author":3,"featured_media":426481,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5123],"tags":[162220,1582,276,198485,115674,2961,87697,224,5337,198486,198489,16361,22299,6773,198488,87395,198487,290,1628],"class_list":{"0":"post-426480","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-los-angeles","8":"tag-atmospheric-river","9":"tag-ca","10":"tag-california","11":"tag-el-nino-confusion","12":"tag-inch","13":"tag-la","14":"tag-la-nina","15":"tag-los-angeles","16":"tag-losangeles","17":"tag-marty-ralph","18":"tag-national-weather-service-define","19":"tag-november","20":"tag-october","21":"tag-rain","22":"tag-record-start","23":"tag-snowpack","24":"tag-southern-california-precipitation-anomaly","25":"tag-state","26":"tag-year"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/115667070335763685","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/426480","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=426480"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/426480\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/426481"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=426480"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=426480"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=426480"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}} <\/p>\n
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