La Niña expected to serve up a hat trick

The weather pattern hits the West for a third consecutive winter.

She’s baaaack! For the past two years, La Niña, the cooling of ocean temperatures in the equatorial Pacific, has wreaked havoc on weather around the globe. Now the World Meteorological Organization expects the phenomenon to return for a third consecutive year, a rare occurrence that forecasters predict could bring wackier-than-usual winter weather to the West, once again. 


La Niña is the yin to El Niño’s yang. Normally, trade winds — the tropical winds near the Earth’s surface — blow west along the equator, moving warm Pacific Ocean water from the Americas toward Asia. This cycle is disrupted every two to seven years by El Niño-Southern Oscillation, or ENSO, events, which typically last about a year. During El Niño, the winds weaken, and warm water is pushed back toward the Americas. La Niña, meanwhile, strengthens trade winds, bringing cool water to the surface of the Americas’ West Coast. 


A study published this summer by University of Washington researchers suggests global warming could be to blame for this year’s La Niña encore. The two weather phenomena have different effects: El Niño tends to bring wetter conditions to the Southwestern U.S., while La Niña usually brings moist, cool weather to the Northwest and hot, drier conditions to the Southwest. 

Still, you might not want to plan your winter around these predictions. Meteorologists have been tracking these phenomena and their impacts on Western weather for about seven decades, but it’s hard to forecast exactly what they mean for any particular location. Pretty much the entire West was unusually moist during the La Niña winter of 2007-’08, for example, and all of it — including the northern regions — saw above-average temperatures last year. When it comes to weather, it’s best to hedge your bets.   

To get some sense of what we might expect this year, we look back on some of 2022’s notable weather events and trends to see how they followed — and diverged from — the expected La Niña patterns.

Number of monthly high-temperature records tied or broken in the West in February 2022. This included a 93-degree Fahrenheit reading in Chula Vista, California, but also several readings in the 70s in Oregon. The Southwest was indeed warm, as is typical of La Niña, but the heat in Pacific Northwest was unusual. Chalk it up to climate change.  

The high temperature in degrees Fahrenheit in Utqiaġvik, Alaska’s northernmost city, on Dec. 5, 2022. That shattered the previous high record of 34 degrees, set in December 1932, and also set a new record mark for the latest date the mercury hit 40 degrees F. It was also only the third December day on record that the temperature climbed above freezing. Much of Alaska is roasting — relatively speaking — under warmer-than-average temperatures so far this winter, even though the La Niña pattern would normally cause the state to be colder than usual.

13.4 inches
Snow water equivalent — a measure of snowpack — in the Upper Colorado River Basin at its 2022 peak on March 23. Normally, the peak is about 16 inches and occurs more than two weeks later. It was, in other words, a dry, warm winter, following the typical La Niña pattern. But by summer’s end, precipitation for the entire water year had risen to the median level, thanks to heavy summer rains — unusual for La Niña.  

Number of acres burned in wildfires in New Mexico by the start of summer 2022, thanks to tinder-dry forests following a meager winter.

Percent of median precipitation the Yellowstone River headwaters received during Water Year 2022 (Oct. 1, 2021, to Sept. 30, 2022), in line with the typical La Niña pattern.

50,000 cubic feet per second
Peak flow of the Yellowstone River at Corwin Springs, Montana, on June 13, 2022, about four times the median flow for the date. This 500-year flooding event was caused by abundant winter snowmelt, combined with an “atmospheric river” storm system that dumped record-breaking rainfall — as much as 3.6 inches in 24 hours — in and around Yellowstone National Park.

July 24
Date that the Rio Grande’s flow through Albuquerque, New Mexico, fell to zero cubic feet per second. While the river often dries up farther downstream, this was the first time since 1983 that it happened that far north.

1,810 cubic feet per second
Flow of the Rio Grande through Albuquerque on Aug. 7, less than two weeks after it had gone dry. An unusually bountiful monsoon dropped 2.48 inches of precipitation on Albuquerque that month, the second-highest monthly amount since 1995.

Number of all-time high temperature records tied or broken in the West during a September heat wave. The temperature exceeded 115 degrees in several cities in Northern California.

1,160 cubic feet per second
Flow of Mill Creek upstream from Moab, Utah, on Aug. 21 following a sudden deluge. The stream had been running at about 15 cfs just moments earlier, and the unexpected torrent flooded Moab streets and businesses. This does not jibe with typical La Niña patterns.

.76 inches
Amount of rainfall in the Phoenix, Arizona, area on Dec. 3, the wettest 24-hour period of the year — not what you’d expect for a La Niña year. Total precipitation in November was just .08 inches.


SOURCES: World Meteorological Organization; National Oceanic and Atmospheric Administration; National Weather Service; U.S. Geological Survey; National Resource Conservation Service; R.C.J. Wills, Y. Dong, C. Proistosecu, K.C. Armour and D. Battisti. S. (2022). “Systematic Climate Model Biases in the Large-Scale Patterns of Recent Sea-Surface Temperature and Sea-level Pressure Change,” Geophysical Research Letters, 49, e2022GL100011. Climate schematics based on those by Emily Eng/NOAA.

Infographic design by Luna Anna Archey/High Country News

Jonathan Thompson is a contributing editor at High Country News. He is the author of Sagebrush Empire: How a Remote Utah County Became the Battlefront of American Public Lands.