ORLANDO, Fla. – Summer’s almost here and the climate’s right for hurricanes.
Forecasters with the National Oceanic and Atmospheric Association say we’ll see La Niña conditions during the 2022 Atlantic hurricane season, which means an active season for storms.
Come later in 2022, we may be hoping for the appearance of La Niña’s opposite, El Niño.
Colorado State University forecasters predict we’ll see 19 named storms, with nine becoming hurricanes and four of those becoming major hurricanes.
While we keep our eyes on the tropical Atlantic this summer, it is conditions out in the Pacific that are dictating the severity of our hurricane season.
The difference between El Niño, La Niña
El Niño and La Niña are actually two phases of a weather phenomenon known as the “ENSO cycle.” ENSO stands for “El Niño-Southern Oscillation.”
The ENSO cycle is a climate pattern off the coast of Peru in South America, in the Pacific Ocean. The pattern shifts back and forth every 2-7 years, and how it shifts affects weather patterns all over the world.
During an El Niño phase, ocean temperatures in that part of the Pacific are warmer than the atmosphere.
During a La Niña phase, the ocean temperatures are cooler than the atmosphere.
Each phase influences atmospheric conditions around the world in different ways.
How the ENSO Cycle in the Pacific affects the Atlantic
In the case of an El Niño phase, circulation expands eastward, creating conditions that produce a trough over the Caribbean and the western Atlantic. This leads to increased vertical wind shear and increased atmospheric stability. Hurricanes do not like vertical wind shear -- it tends to rip storms apart and prevent them from strengthening.
In a La Niña phase, the opposite occurs. La Niña creates conditions that suppress that vertical wind shear. This creates conditions that allow hurricanes to thrive.
The more chances there are of a named storm, the greater the chance of a storm making landfall on the U.S. coast.
Forecasters at Colorado State University predict a 96% chance of a named storm hitting Florida, a 75% chance of a major hurricane striking, and a 44% chance of a major hurricane either nearing Florida or making landfall.
That’s not all La Niña does. It’s a factor in increased severe weather and tornado activity in the southeastern U.S. NOAA says we’ve seen more tornadoes than average this year. It also means less rain and snow over the western and southern U.S., where drought already persists.
Could the atmospheric pattern change?
Right now La Niña is going strong, according to NOAA’s report in May (the agency releases a report every month). Forecasters there say we’ve already seen two La Niña winters, and chances are good we will see a third one. That’s only been recorded two other times before: 1973-1976 and 1998-2001.
That doesn’t mean there isn’t a chance La Niña goes away this season. NOAA says the odds La Niña will drop go from 87% for May to July to 58% for August to October.
Colorado State University forecasters predict La Niña could fall away and we could see what’s called a neutral ENSO cycle this summer, but it’s less likely we’ll switch to El Niño, which would improve our chances of being safe from a hurricane.