(KTLA) – La Niña is expected to stick around for at least a little while longer, with the transition back to neutral conditions most likely not taking place until at least later in spring. That’s according to the latest forecast from the National Oceanic and Atmospheric Administration’s Climate Prediction Center forecast, which was released late last week.
NOAA says there’s an approximately 77% chance that La Niña conditions will linger between March and May. Forecasters also favor the transition back to neutral occurring from June to August, giving that a 57% chance. La Niña typically brings drier conditions to the southern half of the country and more rain and snow to pockets of the northern half.
This is the second consecutive winter with a La Niña event, which compounds a historic drought affecting the American West. The year 2021 was one of the driest in at least 1,200 years for the region, according to a study released Monday in the journal Natural Climate Change.
The winter got off to a promising start with a series of powerful storms that replenished the ever-important Sierra Nevada snowpack and improved California’s overall drought outlook. But January and February have been bone dry for the state, and the snowpack is once again below normal for this time of year.
“The precipitation map for November–January also looks a fair bit like the typical La Niña impacts map for this season. Lots of rain and snow in the Pacific Northwest, substantially drier than average through the south-central and southeastern states,” Emily Becker of NOAA’s CPC wrote in the agency’s ENSO blog.
Since the start of winter, temperatures across California, for example, have also been below average for this time of year, according to NOAA, a phenomenon not shared by some states on the East Coast. “Seasonal climate averages matter—for example, your heating bill is going to reflect if the winter was warmer or colder than average overall,” Becker wrote. “However, sometimes it’s hard to see the forest for the trees, like when you have a December that’s 6 degrees warmer than average, followed by a hairpin turn into a January that’s 2 degrees colder than average.”
La Niña comprises one end of the El Niño Southern Oscillation (ENSO) cycle, and is marked by cooler sea surface temperatures in the tropical Pacific Ocean. On the other end of the cycle is El Niño, which happens when sea surface temperatures are warmer. In between, there’s the third state known as “neutral.”
There have now been five straight three-month periods where the Oceanic Niño Index exceeded the La Niña threshold, which is -0.5 degrees Celsius, NOAA reported. La Niña conditions started to develop last September, and at the time, the agency gave the climate pattern a 50-50 chance of continuing into spring. That prediction, too, appears to be coming to fruition.
Back-to-back La Niña events aren’t necessarily unusual, and experts are already looking ahead to the possibility of conditions developing for a third straight year following a return to ENSO-neutral. However, it’s still too soon to tell whether there will be a three-peat. “We still don’t have a very clear picture of that,” Becker wrote. “By fall (September–November), neutral still has the edge, but forecasters can’t currently give any category a strong chance.”