The National Weather Service has issued a La Niña watch, raising the possibility of the climate pattern developing later this year, according to USDA meteorologist Brad Rippey.
“Back on August 14, the National Weather Service issued a La Nina watch for the possibility, and we’re looking at about a 60% likelihood of this happening, of La Nina forming sometime later this autumn or into the winter months,” Rippey said.
While the current outlook calls for a weak and short-lived La Niña, even a brief episode could have consequences.
“If it does occur, it will be the fifth time in the last six winters that we have seen either La Nina or La Nina like conditions across the central and eastern equatorial Pacific Ocean,” he said.
If La Niña becomes established in the coming months, it could mean worsening drought conditions for parts of the country.
“One of the impacts is to see drought tending to spread, particularly in the western and southern part of the United States,” Rippey noted.
That’s not welcome news for the already parched western U.S. Rippey pointed out that La Niña or La Niña-like conditions have been persistent over the past several years.
“Going back to the winter of 2020-21 and extending through the winter of 2022-23 we saw what we call a very rare triple dip La Nina, where we had La Nina for three consecutive winters. In records going back to the mid-20th century, we have only seen that two other times. Then we followed that a single year with El Nino that lasted from 2023 into 2024 and then during the winter of 2024-25 we saw conditions they got very close to the scientific threshold for defining La Nina.”
That triple-dip La Niña at the start of the decade continues to leave its mark, especially in the West.
“We’re still trying to claw our way out of that drought as we move through 2025. During that triple dip La Nina, we saw a two-and-a-half-year period from late 2020 into early 2023 where we saw more than 40% of the contiguous United States experiencing drought. You get that cool water, it tends to cut off some of the tropical atmospheric moisture from reaching the United States, and that is one of the big reasons we tend to see increases in drought coverage in the western and southern United States during La Nina,” he explained.
Rippey added that the agricultural sector in the South could also feel the effects this winter.
“And as we move into the southern United States, concerns there, as we move on to the winter months, would be impact on range land, pastures, feed for cattle, as well as upcoming winter wheat crop. So certainly, La Nina does come with its set of risks for agriculture.”
Still, Rippey emphasized that a La Niña has not yet formed.
“There is a likelihood of La Nina formation, but certainly we are nowhere near that point. Yet. We’re just starting to see some signs of things happening in equatorial Pacific, pointing us in the direction of La Nina.”