Fall is in full swing, but its not too soon to look ahead to winter, especially one that could feel considerably different than last years .
A weak is expected to develop ahead of the season and influence temperatures, precipitation, and by extension, even snow across the United States.
La Ni単a is a natural climate pattern that influences global weather marked by cooler than average ocean temperatures in the equatorial Pacific. The effects on weather are most pronounced during the winter months in the Northern Hemisphere and have a much weaker influence in the summer.
Last winter was the for the Lower 48 because it was dominated by La Ni単as in a world also warming due to fossil fuel pollution.
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The prolonged warmth prevented many heavyin the and Midwest and created a winter snow drought measured in feet of missing snow.
La Ni単a isnt here yet, but has a 60% chance of emerging through November, according to the Climate Prediction Center. Once it arrives, itll stick around all winter and likely persist into at least early spring of next year.
La Ni単a or El Ni単o are never the only factors influencing weather in a given season or location, but emphasis is placed on them because they typically have an outsized effect on winter weather in the U.S. especially when they are strong.
While its still unclear just how strong La Ni単a will get, current forecasts favor a weaker one.
The strength of La Ni単a matters the stronger it is the more of a consistent impact it can have on weather, according to Emily Becker, an atmospheric scientist at the University of Miami.
A weaker event makes it more likely that other weather and climate phenomena could play the role of spoiler, Becker wrote in .
Earlier forecasts from the Climate Prediction Center show many of the hallmarks of typical La Ni単a winters. That outlook could be change when the center releases its latest forecast on Thursday based on trends toward a weaker La Ni単a.
What could this winter look like?
No two La Ni単a winters are the same, but many have temperature and precipitation trends in common.
This is due to the behavior of the jet stream essentially a river of air that storms flow through which often shifts north during a La Ni単a winter. This typically shifts stormy weather out of the South and into parts of the northern U.S.
Thats almost exactly what the Climate Prediction Centers latest winter forecast shows for December through February.
The entire northern tier of the U.S. is expected to end up wetter than normal this winter, especially the Pacific Northwest, Midwest and parts of the interior Northeast. Wet weather will be crucial to combat ongoing dryness and drought in the Midwest.
Its a from last winters pattern, which favored a wetter South and a drier North.
More precipitation than normal doesnt guarantee there will be more snow. Temperatures still have to be chilly enough both above and at the surface for snow to fall and stick to the ground.
events tend to allow for more snow in the Northeast, while snow is more limited during stronger La Ni単as because warmer temperatures often creep farther up the East Coast.
If this years La Ni単a ends up rather weak, this outlook could shift. Still, the latest winter temperature forecasts from the center arent ideal for snow lovers in the Northeast.
The season is expected to be warmer than normal across almost the entire southern half of the U.S. and much of the East. This could mean some winter storms in parts of the East end up wetter, rather than snowier. But with drier and warmer than normal conditions expected across the South, drought conditions could worsen throughout the season.
Parts of the Midwest, Plains and Rockies could end up with temperatures closer to normal this winter while cooler than normal conditions are expected from the Pacific Northwest to parts of the Dakotas.
The combination of wetter and cooler than normal conditions could potentially mean more snow for the Pacific Northwest, an area where a significant snowpack is crucial to in the winter and the for the warmer months.
Northern California is typically wetter during a La Ni単a winter, but the Climate Prediction Centers forecast keeps the region near normal this season. La Ni単a had a hand in the much of the state endured from December 2022 to February 2023 and during the wet winter before that.
Southern California is expected to be drier and warmer than average typical for La Ni単a. Its crucial the region gets a period of soaking rain in the next few months; wet weather is needed to shut down wildfire season. Without enough rain, fires could continue to burn through the like grasses or brush available this year.