La Niña conditions have returned, the National Oceanic and Atmospheric Administration announced Thursday, and will likely stay around through the winter.
La Niña is a weather pattern marked by cooler sea surface temperatures in the central and eastern Pacific Ocean. It usually brings colder temperatures and more rain to the Pacific Northwest and northern Plains and drier and warmer conditions in the South and Southwest — unwelcome news for drought-stricken California.
"La Niña is associated with reductions in vertical wind shear in the Caribbean and tropical Atlantic," Colorado State University research scientist Phil Klotzbach told CNN. "Too much shear is typically what ends the Atlantic hurricane season, so La Niña can extend the active part of the season."
While La Niña typically lowers global temperatures, the Earth has been warming so fast in recent years that it's unlikely this will make much of an impact.