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La Niña is expected to develop towards the end of the year, meaning a warmer and drier winter.

Posted on by L. Dreeye
La Niña is expected to develop towards the end of the year, meaning a warmer and drier winter.

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La Niña has flirted and retreated, teased and taunted, giggled and scolded, but scientists still believe the global climate pattern will emerge in the final weeks of 2024, bringing a warmer, drier winter to South Florida.

The seasonal forecast released by the National Weather Service and South Florida Water Management District on Nov. 18 said there is a 57% chance that La Niña will develop and persist through March 2025.

Traditionally, La Niña means extended dry spells for South Florida during the darkest days of the year, an increased threat of drought and wildfires, and temperatures that are 1 to 3 degrees above normal. During La Niña winters, precipitation is typically 10 to 30 percent below normal.

“All forecast models point to warmer-than-normal temperatures well into April,” said Robert Molleda, a meteorologist with the NWS Miami office. “Each of the previous eight La Niña winters resulted in moderate to severe spring drought in at least parts of South Florida.”

But this La Niña has been hinting at a debut since February, when the Climate Prediction Center, an office of the National Oceanic and Atmospheric Administration, issued a La Niña watch. The forecast at that time gave a 55% chance of the atmosphere-altering event awakening in early summer and a 74% chance of developing before October.

It was a no-show.

“Not every event is so easy to predict,” Molleda said. “We’re used to some pretty simple and well-defined events, and we’ve had a few of those over the last five to 10 years, but many times in the past the signals weren’t that well-defined.”

What are the weather conditions of El Niño and La Niña?

The El Niño and La Niña climate patterns are part of the powerful El Niño-Southern Oscillation, or ENSO.

La Niña occurs when waters in the equatorial Pacific Ocean cool, shifting when and where tropical thunderstorms form so that wind shear in the Atlantic Ocean weakens during hurricane season, giving incipient tropical cyclones more freedom to grow.

In winter, La Niña sends storms into the Pacific Northwest along a more northerly and inland path, keeping the jet stream longer at higher latitudes, where it traps cold air northward.

During El Niño, equatorial waters warm up. In the summer, El Niño creates wind shear that breaks apart Atlantic tropical cyclones. In the winter, El Niño pushes the jet stream south, which traditionally makes Florida winters cooler and wetter.

More: South Florida’s cloudy winter ends with coolest in years thanks to El Niño

But there is no guarantee that any climate model will behave as predicted.

Pacific Ocean temperatures did drop last summer, but not as much as scientists expected and not the 0.9 degrees below the long-term average needed for a La Niña to really cause problems in the tropics.

That doesn’t mean it hasn’t been an active hurricane season, which ends on November 30th.

There were 18 named storms through Nov. 19, four more than the annual average. These included 11 hurricanes and five major hurricanes. In particular, three hurricanes—Category 1 Debbie, Category 4 Helen, and Category 3 Milton—made landfall along the Florida Gulf Coast.

“In the end, it didn’t matter if La Niña was here during the tropical season,” Da Silva said. “It didn’t have much of an impact.”

And it may not have a significant impact this winter. Because La Niña is so late, it won’t have much time to strengthen, said Emily Becker, associate director of the Cooperative Institute of Marine and Atmospheric Science at the University of Miami.

Becker blogs for NOAA about the El Niño Southern Oscillation. She said only two La Niña events in its 75-year history have occurred between October and December.

A weak La Niña means other weather patterns could usurp its dominance, producing severe thunderstorms despite overall lower chances for severe weather.

The most recent La Niña event was a violent EF-2 tornado that struck Palm Beach Gardens and North Palm Beach in April 2023. This was preceded by historic flooding in Fort Lauderdale, when more than 25 inches of rain closed the Fort Lauderdale-Hollywood Road. The international airport and areas remained under water for several days.

During La Niña in 2016–2017, three tornadoes struck southeast Florida, including one that tore through Palm Beach Gardens and Juneau Beach with maximum wind speeds of about 90 mph.

“The only thing we can say for sure is that nature will keep us guessing,” Becker said in her blog about La Niña. “We’ve said it for months and we’re saying it again: Forecasters still believe La Niña will develop and last through the winter.”

Kimberly Miller is a Florida journalist for The Palm Beach Post, part of the USA Today Network. She covers real estate, weather and the environment. Subscribe to The Dirt for weekly real estate reviews. If you have news tips, send them to [email protected]. Help support our local journalism by subscribing today.