NOAA predicts another La Niña this winter: when will it arrive and which areas will it affect?
For the third year in a row the agency’s Climate Prediction Center has suggested that unseasonably warm conditions will arrive in parts of the US.
The National Oceanic and Atmospheric Administration (NOAA) has confirmed that La Niña is expected to arrive in the United States this winter, bringing warmer-than-average temperatures in certain areas for the third consecutive year.
Each year the NOAA’s Climate Prediction Center releases a Winter Outlook report. This year’s edition predicts that there will be La Niña conditions in effect from December 2022 through February 2023.
Temperatures in the southwest and along the Gulf Coast will be warmer than usual, as a result of La Niña’s warm winds. Southern parts of the US will also likely experience wetter-than-average conditions, particularly in areas of the Ohio Valley, Great Lakes, northern Rockies and Pacific Northwest.
“Drought conditions are now present across approximately 59% of the country, but parts of the Western US and southern Great Plains will continue to be the hardest hit this winter,” said Jon Gottschalck of the NOAA’s Climate Prediction Center. “With the La Niña climate pattern still in place, drought conditions may also expand to the Gulf Coast.”
What is the La Niña weather phenomenon?
La Niña, or ‘the girl’ in Spanish, is climate phenomenon that is caused by strong trade winds in the Pacific. These powerful gusts push warm water towards Asia and bring cold, nutrient-rich water to the surface close to the Americas.
This has the effect of pushing the Pacific jet stream further north, reducing the amount of precipitation experienced in the south and causing heavy rains and flooding in the northwest and parts of Canada.
The movement of the usual wind patterns tends to make it warmer and drier in the south of the United States, and colder and wetter in the north.
Another consequence of La Niña is to bring nutrient-rich colder waters to the surface near the Pacific coast of the US. This attracts more marine life and cold-water species to the areas like the California coast.
While the effects of La Niña have been felt in recent years, there is a related phenomenon that brings warm waters to the Pacific coast. El Niño brings unusually warm waters western parts of the US and pushes the jet stream south of its usual position.
This has the opposite effect of La Niña, and brings drier and warmer conditions in the north and wet and cold weather for the south. It also halts the uprising of nutrient-rich waters than many organism rely on, affecting the local environment.