It remains to be seen how strong this iteration of El Ni\u00f1o could be. There\u2019s up to a 37% chance that it will be \u201cvery strong<\/a>\u201d by the end of the year, up from a forecast of 25% issued last month.<\/p>\n There\u2019s also a 30% chance El Ni\u00f1o will be \u201cstrong,\u201d a 22% chance it\u2019ll be \u201cmoderate,\u201d and a 9% chance it\u2019ll be \u201cweak,\u201d forecasters said.<\/p>\n A number of forecasting models suggest \u201ca pretty substantial El Ni\u00f1o\u201d will come, according to Marty Ralph, director of the Center for Western Weather and Water Extremes at the Scripps Institution of Oceanography at UC San Diego. <\/p>\n \u201cIt\u2019s got a pretty good chance of being well above the El Ni\u00f1o threshold in a sort of modest way, and then some possibility that it\u2019s far above,\u201d he said earlier this week. <\/p>\n (Paul Duginski \/ Los Angeles Times)<\/p>\n Just three weeks ago, the World Meteorological Organization said it saw a clear shift in sea-surface temperatures in the equatorial Pacific, an indication that El Ni\u00f1o\u2019s arrival is imminent. <\/p>\n \u201cThere is high confidence in the onset of El Ni\u00f1o, followed by further intensification in the months that follow,\u201d Wilfran Moufouma-Okia, the organization\u2019s chief of climate prediction, said in a statement<\/a>. \u201cModels indicate that this may be a strong event.\u201d <\/p>\n He noted, however, that forecasts are developing and could still change. But Thursday\u2019s announcement indicates that the chances of a powerful El Ni\u00f1o have continued to rise. <\/p>\n El Ni\u00f1o is one of the most powerful climate patterns on Earth, capable of reshaping global weather and affecting rainfall and drought, according to the WMO. It typically hits every two to seven years and lasts around nine to 12 months. <\/p>\n A typical El Ni\u00f1o is linked with higher-than-average precipitation in Southern California, according to the National Weather Service. A strong El Ni\u00f1o can shift a subtropical jet stream that normally pours rain over the jungles of southern Mexico and Central America toward California and the southern United States.<\/p>\n While it\u2019s no given that El Ni\u00f1o will bring a potent rain season to Southern California, some previously high-powered patterns have been monsters.<\/p>\n There have been only three \u201cvery strong\u201d El Ni\u00f1os in the past half-century, in 1982-83, 1997-98 and 2015-16. The first two brought huge and destructive amounts of precipitation to the Golden State. <\/p>\n In early 1998, storms brought widespread flooding and mudslides, causing 17 deaths and more than half a billion dollars of damage in California. Downtown L.A. got nearly a year\u2019s worth of rain in just one month. At least 27 homes were so severely damaged that they could not be safely occupied along the coast, according to the California Coastal Commission<\/a>.<\/p>\n During the winter of 1982-83, damage was particularly severe along the coast as high tides surged amid powerful storms. About $100 million in damage was reported. The U.S. Army Corps of Engineers reported<\/a> 33 oceanfront homes were destroyed and another 3,000 houses, as well as 900 coastal businesses, were damaged by storm surges, waves, erosion and other forces.<\/p>\n But the 2015-16 El Ni\u00f1o<\/a> \u2014 while strong in the equatorial Pacific \u2014 didn\u2019t bring the anticipated rainfall effects to Southern California, and failed to snap the state out of a punishing five-year drought. That water year actually saw below-average rain in the region, and either average or above-average precipitation in Northern California. <\/p>\n However, that El Ni\u00f1o \u201cdid cause record coastal erosion along many California beaches,\u201d according to the Coastal Commission. <\/p>\n Impacts of that season\u2019s El Ni\u00f1o were far more consequential elsewhere. There was a \u201crecord-smashing hurricane season in the central North Pacific,\u201d with 16 tropical cyclones through the unusually warm ocean \u2014 more than triple the average, according to<\/a> the National Oceanic and Atmospheric Administration. There were also severe droughts in the Caribbean \u2014 so much so that 65% of Antigua\u2019s farmers went out of business, with a 1-billion-gallon reservoir going dry. <\/p>\n Therein lies a big asterisk about El Ni\u00f1o. Since 2000 or so, Ralph said, \u201cthe traditionally expected relationship between El Ni\u00f1o, La Ni\u00f1a, Southern California and winter wetness has gone the other way. The El Ni\u00f1os have not been extremely wet, and the La Ni\u00f1as have been extra wet.\u201d <\/p>\n During La Ni\u00f1a, the sea surface temperatures of the central and eastern Pacific Ocean cool \u2014 the opposite of the El Ni\u00f1o trend. The jet stream also shifts northward, typically pushing winter storms toward the Pacific Northwest and Canada while leaving swaths of California drier than average, especially in the south.<\/p>\n Ralph coauthored a scientific paper that sought to understand specifically why 2010-11, 2016-17 and 2022-23 were very wet years in California despite the existence of La Ni\u00f1a. As it turns out, El Ni\u00f1o and La Ni\u00f1a aren\u2019t the only players in determining how much rain and snow fall over Southern California. <\/p>\n The El Ni\u00f1o\/La Ni\u00f1a pattern probably does influence certain storms that hit California, but only the typical seasonal variety that originate from Alaska or north of Hawaii, Ralph said. What El Ni\u00f1o and its colder sibling pattern don\u2019t affect, however, are \u201catmospheric rivers,\u201d which can carry tremendous amounts of precipitation to California from the tropics, Ralph said.<\/p>\n Those types of storms have been increasingly prevalent in recent years, fueling powerful winter storms even without the presence of El Ni\u00f1o.<\/p>\n For instance, last fall brought with it another La Ni\u00f1a, and an expectation for a dangerously dry winter for Southern California. Instead, the season was wetter than average. . <\/p>\n But El Ni\u00f1o in 2023-24, which was characterized as \u201cstrong,\u201d did bring with it a pretty wet year for Southern California, with downtown L.A. receiving 155% of its typical annual rainfall. That February, there was record precipitation and a memorable five straight days of rain<\/a> that triggered hundreds of mudslides in L.A. alone. Dozens of homes and buildings were damaged by debris flow, including 15 homes that were red-tagged. <\/p>\n While El Ni\u00f1o doesn\u2019t always perform as expected for Southern California, some experts still find value in using its arrival as a scene-setter for potential weather impacts. El Ni\u00f1os are typically associated with more precipitation for parts of southern South America, central Asia and the Horn of Africa, according to the World Meteorological Organization and National Weather Service. It\u2019s also linked with drier weather<\/a> in Washington, Oregon, Idaho and Alaska, as well as the Ohio River Valley<\/a> in the Midwest and upper South, as well as in Australia, Indonesia, and parts of southern Asia. <\/p>\n <\/p>\n