ND Winter Outlook 2022-23: rare triple-dip La Niña could lead to below normal temps and above normal snow
BISMARCK, N.D. (KFYR) - This week is North Dakota’s Winter Weather Awareness Week and many of us are wondering what’s in store for the upcoming winter.
Meteorologists often turn to ocean temperatures in the Pacific Ocean near the equator to determine if an El Niño or La Niña is present when creating a winter outlook. With a La Niña, stronger than normal winds in this part of the world push warmer water westward, allowing for cooler water to come to the surface farther east.
Current sea surface temperatures show this region of cooler than normal water, indicating that La Niña will continue for a rare third year.
This impacts the jet stream pattern, leading to downstream effects in the United States, generally meaning that the winter will be colder than normal in the Northern Plains.
“We see this blocking high pressure in the north Pacific. That leads to a more variable polar jet stream, so it kind of arcs up into Alaska and then down into Canada and the north-central U.S. So it makes it a lot easier for that cold air to make it into the north-central U.S.,” said Megan Jones, a meteorologist at the Bismarck National Weather Service.
Looking back at the only four times a triple-dip La Niña has happened in record-keeping history, three of the times below-normal temperatures were found here during the third La Niña winter.
In our past two winters with La Niña present, above normal temperatures were seen two years ago, with the exception of a cold February, and below normal temperatures were mostly experienced last year.
“Comparison to last winter, I would expect a similar transition temperature-wise where we were pretty mild through the fall, and we’ve been doing that. And then this transition month during December, before we really settle into that typical North Dakota winter, January, February, March, and even into later in the spring, there is a pretty good signal for that cold to stay around for a lot longer than we would want it to,” said Jones.
As for snowfall, the confidence in this isn’t as high as it is for the cold, but there are signals that the La Niña could weaken heading into the spring which could favor more precipitation and snow in the second half of winter.
“But it stood out to me that there’s enough of a signal in the extended guidance and the typical La Niña patterns, especially for that weak La Niña, we could end up with a more active second half of the winter and potentially into the spring season,” said Jones.
While La Niña indicates that a cold and possibly snowy winter is ahead, it’s important to remember that there are many other factors and connections in other parts of the globe to investigate when creating the overall outlook.
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