La Nina, known for its cooler ocean temperatures and often stronger weather impacts compared to El Nino, has officially arrived, meteorologists announced Thursday. This natural climate pattern usually boosts the Atlantic hurricane season, but this year’s event appears weak and may not stir up much trouble.
La Nina happens when parts of the Central Pacific Ocean cool by about half a degree Celsius. This shift changes weather patterns around the world. In the U.S., it usually means more rain and snow up north and drier conditions in the South. Other parts of the globe, including Indonesia, Australia, and parts of Africa, often see heavier rains. Meanwhile, regions like the Middle East and eastern Asia can face drought.
Officials from the National Oceanic and Atmospheric Administration (NOAA) say this La Nina is likely to be mild and short-lived. Computer models suggest it could fade in a few months. Michelle L’Heureux, who leads NOAA’s La Nina and El Nino research team, said there’s about a 75% chance the event will remain weak. She added that a weaker La Nina usually means less impact on global weather, so surprises remain possible.
This year’s Atlantic hurricane season was expected to be more active than usual due to La Nina, which typically lowers wind shear and allows hurricanes to grow stronger. But so far, the season has been quieter than expected. Experts like Brian Tang from the University at Albany note that La Nina often makes hurricanes stronger later in the season, especially from late October to early November in the Caribbean. Still, some researchers, such as Brian McNoldy from the University of Miami, believe this La Nina is too weak and late to make much difference.
Colorado State University hurricane expert Phil Klotzbach pointed out that while the conditions favor more storms, the usual increase in hurricane activity hasn’t appeared yet and isn’t expected soon.
Last winter included another weak La Nina, which showed some effects but mainly stayed mild. Research shows that La Nina events can cause more costly weather damage in the U.S. than El Nino. A 1999 study found La Nina droughts cost American agriculture between $2.2 billion and $6.5 billion, far more than the $1.5 billion linked to El Nino.
Azhar Ehsan, a research scientist at Columbia University who oversees El Nino and La Nina forecasts, said that although a cooler La Nina isn’t always pricier, it often is.
The appearance of this new La Nina will keep scientists watching weather patterns around the world closely, but for now, its impact seems mild compared to past events.