By: Jordan Park

Local Editor

Weather analysts predict a historically strong El Niño winter to return to the California coast. El Niño is a climate pattern that occurs when warm water builds up in the Pacific Ocean near the equator, causing changes in wind patterns and the distribution of warm and cold water. An El Niño winter is characterized by above-average sea surface temperatures in the central and eastern Pacific Ocean, which can lead to intense storms, rainfall, wind, and snow in various parts of the world, including the US. 

While this weather will keep the state out of a drought, experts are concerned that with the already saturated conditions from last year’s winter and surplus of rainfall, there is an increased possibility of floods and mudslides.“We didn’t have any big floods on the main rivers because the reservoirs had been drawn down tremendously from the previous three years of drought,” said Jay Lund, a professor of civil and environmental engineering at the University of California at Davis, in an interview with The Washington Post. He added, “The extra flood control that you have coming out of a drought is now full of water for this year.” Lund exemplifies his concern, stating, “There is very little correlation from one year to the next about how much water you are going to get, you really have to be prepared for floods or drought — or both — in the coming year.”

The most recent El Niño event occurred in the winter of 2018, and weather scales considered the event weak, with water temperatures in the Pacific Ocean only reaching between one-half and one degree Celsius above average. This resulted in above-average rainfall and over a year of warm temperatures in the US, but the impact was not as severe as in previous events. The El Niño event in 2015 was one of the strongest ever recorded, with sea surface temperatures in the central and eastern Pacific Ocean reaching more than two degrees Celsius above average. This led to widespread droughts in some parts of the world, such as Indonesia, and heavy rainfall and flooding in others, including South America. 

Growing climate change may factor into El Niño events; there is evidence that suggests that climate change could affect their frequency and intensity. In recent months, the world’s oceans have experienced above-average temperatures, not just limited to the Pacific. The impact of this phenomenon on weather patterns and the potential counter-effects on the typical symptoms of El Niño remain uncertain. It is also expected that there will be more frequent swings from a strong El Niño to a strong La Niña the following year. La Niña is a cooling of the ocean surface temperature in the central and eastern tropical Pacific Ocean, which can cause changes in global weather patterns that are generally opposite to those of El Niño. This can result in drier-than-normal conditions in some areas and increased rainfall and flooding in others. La Niña can also cause more frequent hurricanes and tropical cyclones in some regions. 

The probability of a wetter winter and spring in California has increased due to El Niño, leading California to put aside about 52 million dollars for levee repairs, set up longer temporary flood walls, and procure millions of additional sandbags in preparation for potential winter-related hazards.

(Sources: CNN, Climate.gov, Fox Weather, The Washington Post)