La Niña is back.
It’s been a couple of years since satellites and buoys detected the mass of cold water forming along the equator. National Weather Service meteorologist Alex Tardy said when you average out the effect of La Niñas over the last few decades, they tend to indicate we’re in for less precipitation than what we’d get in an average winter.
The National Weather Service says that conditions are in place for a La Niña weather pattern in the fall and winter of 2020-21. That could bring warmer, drier than usual weather to San Diego over the next few months.
By definition, La Niña happens when the water along the equator is colder than usual. That pushes the jet stream farther north and directs storms away from the Pacific Southwest region of the United States.
As historic wildfires continue to burn across California, Oregon and other Western states, government climate experts say much of the U.S. is likely to see persistent drought conditions and fire risk alongside continued above-average temperatures through the fall.
During a briefing Thursday, forecasters with the National Oceanic and Atmospheric Administration said that while wetter conditions are expected to bring some drought relief to parts of the Pacific Northwest and New England in the months ahead, drought conditions are likely to persist or even worsen in Central and Southern California and across the Southwest.
Climate forecasters said Thursday that the world had entered La Niña, the opposite phase of the climate pattern that also brings El Niño and affects weather across the globe. Among other impacts, La Niña has the potential this winter to worsen what are already severe drought conditions in the American Southwest.
La Niña — which often means a busier Atlantic hurricane season, a drier Southwest and perhaps a more fire-prone California — has popped up in the Pacific Ocean.
The National Oceanic and Atmospheric Administration announced Thursday that a La Niña, the cooler flip side of the better known El Niño, has formed. Meteorologists had been watching it brewing for months.
A natural cooling of certain parts of the equatorial Pacific, La Niña sets in motion a series of changes to the world’s weather that can last months, even years. This one so far is fairly weak and is projected to last through at least February but may not be the two-to-three-year type sometimes seen in the past, NOAA Climate Prediction Center Deputy Director Mike Halpert said.
La Niña conditions were observed in the Pacific Ocean last month, and there is a 75% chance the weather pattern will persist through the winter, forecasters with the National Oceanic and Atmospheric Administration said.
Odds increasingly favor a La Niña weather pattern taking hold by fall, upping the chances for a cold and wet Northwest winter, the National Weather Service’s Climate Prediction Center says.
The center pegged at 60% the chances of a La Niña prevailing in November, December and January. A month ago, the center put the chances at 53%.
Federal weather forecasters on Thursday predicted the development of drought-producing La Niña pattern that could to last through the winter.
There is a 60% chance that La Niña will develop during the Northern Hemisphere fall, with a 55% chance the pattern will continue through the winter of 2020-21, the National Weather Service’s Climate Prediction Center said in its monthly forecast.
The National Oceanic and Atmospheric Administration issued a La Niña watch earlier this month, meaning that conditions are favorable for development of a La Niña in the next six months.
The Water News Network is San Diego County’s source for water news and information.
