Are we in an El Niño or La Niña year? What this winter could mean for Idaho weather
Idaho’s upcoming winter is forecast to be average to slightly colder than usual, according to experts, as climate patterns steer the state.
One of those climate patterns is El Niño and La Niña, a weather phenomenon that occurs in the Pacific Ocean and can affect global weather. Here’s what the two weather patterns mean and how they will affect Idaho this winter.
A historic La Niña
We’re in for another year of La Niña.
A La Niña occurs when the temperature of the sea is cooler than average in the Eastern Pacific, resulting in less evaporation, weaker storms and less moisture in the atmosphere, according to the National Oceanic and Atmospheric Administration. Its counterpart, El Niño, is when warm water moves toward the West Coast.
David Groenert, a lead meteorologist at the National Weather Service in Boise, told the Idaho Statesman that this will be the third consecutive year with a La Niña weather pattern. It’s an extremely rare occurrence to happen three years in a row, Groenert said, with the only two other times it’s happened on record being from 1973 to 1976 and 1998 to 2001.
La Niña conditions typically span about 9 to 12 months but can go as long as two years, according to NOAA.
“It typically ping pongs back and forth, in general, from one to neutral to the other and back,” Groenert said. “Sometimes you do get return years, but to get a third return year, I don’t know if anyone really knows as to why that’s the case.”
According to the National Centers for Environmental Prediction’s Recent Evolution, Current Status and Predictions, La Niña will continue through the Northern Hemisphere from winter 2022 to 2023.
What does this mean for Idaho?
Falling in line with what is predicted by the Farmers’ Almanac, Groenert said that Idaho would experience below-average temperatures and above-average precipitation this winter. That will mean more snow for the mountain regions and a good possibility for above-average snow in the Treasure Valley.
“Definitely the mountains (it’ll snow more), and it’s always harder to say for the valleys,” Groenert said. “But in general, yes, compared to average, we’re more likely to see above-average snowfall.”
The effect of a La Niña depends on the region. According to NOAA, a typical weather pattern during a La Niña is cool and wetter than average temperatures in the Pacific Northwest and warmer and drier than average weather in the southern U.S.
“For an El Niño, that’s going to focus the precipitation further south. So for us, so a milder winter,” Groenert said. “Usually for a La Niña, the storm track takes up moisture and puts it more towards the north, and we also get into a colder air current as well from the north.”
