There's a 55 to 65 percent chance that weak La Niña conditions could develop in the Pacific ocean in the coming months, which could mean drier and warmer weather conditions in Southern California this winter, according to the National Oceanic and Atmospheric Association.
"At this point we're probably more confident that you'll be warmer than average this winter. There is a fairly slight tilt towards a dry winter," said Mike Halpert, deputy director of NOAA's climate prediction center, about Southern California.
This year, the chance that the region will see below, average or above average precipitation is a tossup, he said. However, there's a 45 percent chance that we'll have above average temperatures.
"Of course, I believe we had a slight tilt toward a dry winter last year and we know how that ended up," said Halpert.
Last year, slight La Niña conditions were also present, but California was bombarded by a deluge of storms that set record rainfalls across the state, alleviating drought conditions in most areas while also causing widespread damage. Halpert said that there's only a five percent chance that those record-setting rains will happen again.
Climatologists look for the development of El Niño and La Niña climate patterns in the Pacific to inform their models, because of the outsized impact that they can have on weather around the world. La Niña conditions are signaled by the cooling of waters in the tropical Pacific, while El Niño is associated with warming. The former can result in drier conditions for Southern California, while the latter can result in more rain than usual.
However, climate predictions aren't always correct. Besides the record-setting precipitation levels during a La Niña year in 2016-2017, the so called Godzilla El Niño of 2015-2016 was expected to bring buckets of water, but the season came and went and California remained parched.
"There are some variations in the atmosphere are really really hard to foresee more than a couple of weeks in advance," said Daniel Swain, a climate scientist at UCLA. "But then there’s also the possibility that there are things that we're missing. And we clearly don’t have a perfect understanding of the links between what’s going on in the ocean and the atmosphere."
"It’s also the case that the ocean and the atmosphere are both changing," he said. "And we’re living in a world where the relationship between the warming oceans and the warming atmosphere are not necessarily what it used to be. And scientists are still grappling with that."