After a four-year hiatus, El Niño is expected to make a big comeback this summer, ushering in the possibility of another wet and stormy winter.
“It looks like it’s going full steam ahead,” UCLA climatologist Daniel Swain said in a live YouTube interview last week, putting the probability of a strong El Niño event at more than 50%, even as projections they still vary widely.
“A strong event has the potential to have a strong impact in California,” Swain said.
The El Niño weather phenomenon, the opposite of La Niña, typically occurs every three to five years when ocean waters along the equator in the eastern Pacific warm by at least half a degree Fahrenheit.
That, in turn, can reposition the jet stream and funnel storms toward the West Coast, often resulting in increased precipitation for thousands of miles, said John Monteverdi, emeritus professor of meteorology at the San Francisco State University.
But a wet winter is by no means guaranteed, he said, noting that only one of six current models predicts a strong El Niño as this year progresses.
“People have been delighted to believe that all El Niños mean storms,” Monteverdi said. “The historical record does not support a safe bet on that.”
Misconceptions abound about this mysterious weather pattern. Below are six of the most common.
Misconception 1: El Niño Hits California
Every time Jan Null reads a headline that El Niño is hitting the West Coast, she cringes. The local meteorologist, who founded the Golden Gate Weather Service, said the headlines are not factual because El Niño actually occurs “about 3,000 miles away from California. It is not moving en masse toward the California coast.” However, it can greatly affect the weather in California.
Misconception 2: Every El Niño event and its effects are identical
Over the more than seven decades that El Niños have been tracked, their strength and impact have varied significantly, with many having little impact in California.
“The general idea is that El Niño brings wetter winters in California, although the relationship is somewhat fragile,” said John Chiang, a UC Berkeley climatologist. “In reality, only strong El Niño events affect precipitation in Northern California.”
And a host of other oceanic and atmospheric variables can enhance or mitigate the effects of El Niño, noted meteorologist Null, saying: “I’ve often referred to it as the alphabet soup of all this other weather stuff that’s going on. “.
Misconception 3: El Niño is a storm
“El Niño is not a storm in and of itself,” Monteverdi said.
Rather, he explains, it is a phenomenon that can prepare the atmosphere to push stronger storms toward the West Coast.
El Nino “does not create storms” and “does not create storms directly over California or anywhere else,” Null added.
Misconception 4: El Niño always results in catastrophic flooding
Significant flooding is likely to occur in a non-El Niño period like the one Californians experienced last winter (which was technically a La Niña year).