Farmers across the U.S. are gearing up for a potentially volatile winter as the National Weather Service has placed the country under a La Niña Watch. But what does that really mean for the months ahead? Eric Snodgrass, principal atmospheric scientist for Nutrien Ag Solutions, says this winter’s pattern could be one to watch closely.
Weather Highlights from Now Through December
- Expect an early-peaking La Niña, with the strongest impacts likely around Christmas.
- Look for cold, snowy conditions in the north and dryness in the south.
- Watch for frequent Arctic intrusions and an active Ohio Valley storm track.
- Recharging soil moisture before freeze-up is critical, especially in the Midwest.
- Persistent Cotton Belt drought could influence next summer’s Corn Belt outlook.
- South America faces a wetter north/drier south split, which could affect global crop markets.
What a La Niña Watch Means
The Climate Prediction Center says there’s a 71% chance of La Niña conditions developing from October through December. CPC also issued a La Niña Watch, which means conditions are favorable for the development of La Niña within the next six months.
“La Niña just means the trade winds are fast across the equator,” Snodgrass explains. “When that happens, it tends to give us a very loopy jet stream throughout winter.”
That looping pattern is something Snodgrass says influences everything from temperature swings to precipitation.
“When you think about La Niña winters, they all have different flavors,” he says. “We’ve had four La Niñas in the last five winters. This would be the sixth one in that time frame. And the big question we have is: Is it going to deliver typical La Niña conditions?”
Historically, La Niña brings colder and snowier conditions across the northern U.S. and drier conditions in the South.
“We typically find that we’re dry from the Southwest, the Sun Belt to the Cotton Belt,” Snodgrass says. “We tend to be snowier and colder to the north — across parts of the Pacific Northwest, Northern Plains, Midwest and Great Lakes. La Niña winters tend to be cold, tend to snow, but that’s not a guarantee — it’s a tendency.”
Early Peak, Quick Exit
This year’s La Niña is expected to be relatively short-lived.
“We think it’s going to peak early, probably right around Christmas, and probably quickly exit,” Snodgrass notes. “The big question I have is: What’s going to happen to the drought monitor between now and next April when we’re thinking about a La Niña winter?”
Moisture Deficits Are a Big Concern
Moisture is already top of mind for many growers. After an unexpectedly wet spring in some regions, conditions turned dry quickly, leaving soil moisture depleted.
“We need to get a lot of moisture before the ground freezes in parts of the Midwest,” he says. “If we can do that, we’ll lock that in and save it for spring.”
But getting there might involve a bumpy ride.
“There are a lot of indications right now that this winter could be fun,” Snodgrass says with a laugh. “When I say fun, that’s fun for me to forecast. That means most people don’t like those kinds of winters. They’re probably going to be pretty volatile — frequent but brief intrusions of really Arctic air.”
He says we recently saw a hint of that with the rain that hit the East Coast last week.
“That’ll set up an active storm track through the Ohio Valley most likely. We already saw our first nor’easter go up the East Coast just last weekend, and you look at all of that and you’re going, is this kind of the way things are going to shake down,” he adds.
If the pattern develops as expected, it could dramatically shrink drought coverage, which currently is covering 73% of the continental U.S.
“You add La Niña into the mix, and it could be a winter that takes the drought monitor from 73% maybe down to 43% or even below that,” he explains. “But the question will remain: Where did the drought stick around?”
Snodgrass is particularly concerned about lingering drought in the South.
“What I always worry about with La Niña winters is if Cotton Belt drought survives, especially in the Delta. And if it’s there by the time we get to spring, then I start to worry about Corn Belt drought the next summer,” he says. “So yes, this is going to be a critical winter for us.”
Analog Years Point to a Volatile Pattern
When asked about potential analog years, Snodgrass points to a recent and familiar one.
“The best analog is actually last year, 2024, which is kind of funny,” he says. “There are five different areas around the globe, and the ocean temperatures, plus the fall drought in the Mississippi basin, plus what’s going on in the Indian Ocean, plus what’s going on in South America — all of these things are like, hey, we just saw this. It was called last October, November.”
That year brought some memorable weather swings. Does that mean we should set ourselves up for a mild rest of fall and then a brutally cold January and February where it snows as far south as New Orleans? That’s what the U.S. experienced last winter, followed by a super wet spring.
“I hate to say it, but 2024 is kind of setting itself up to be an interesting analog to this year,” Snodgarass says. “But like I said, there’s no such thing as a perfect analog — we’ll have to sit and wait to see how it all unfolds.”
South America’s Split Forecast
La Niña’s impacts won’t be confined to the U.S.
“It tends to split South America from Brazil to Argentina,” Snodgrass explains. “Brazil tends to have a decent monsoon — tends to be wetter. They tend to love La Niña if you’re in the Cerrado. If you’re in southern Brazil, they start to get worried. They tend to see drier conditions. You get into Argentina, historically, it’s drier.”
Some areas have already received favorable early rains, while others are still waiting for the monsoon to ramp up. Not only have areas of Brazil seen good rains, but they’ve also been able to plant at a rapid pace.
“And others are going, wait a minute, we haven’t seen this monsoon get really going yet, and they’re waiting. I think it’s going to be a north versus south issue — wetter north, drier south,” Snodgrass says.
