The last three winters have been dominated by La Niña, which typically means a dry winter in the southern half of the country and colder, wetter conditions in the Pacific Northwest. But that’s not the case this year, as a strong El Niño looks very likely to stick with us through early next year.How will El Niño affect winter? New long-range outlook released
NOAA outlook for winter temperatures
This year the CPC, which is part of the National Oceanic and Atmospheric Administration, is forecasting above-normal temperatures across the northern United States through the winter months.
Central Illinois is predicted to experience slightly above-normal temperatures. The best chance for a warmer-than-normal winter to occur is in the Northeast, the Pacific Northwest and the upper Great Lakes states.
For the southern half of the country, the temperature outlook for December, January and February shows that there’s an equal chance for temperatures to be normal, above normal or below normal.
NOAA outlook for winter precipitation
The Climate Prediction Center is forecasting drier-than-normal conditions for much of the northern United States between December and February. In particular, the Pacific Northwest and the Midwest have the best chance for drier than normal winter months.
Central Illinois seems likely to experience an equal chance for precipitation to be normal, above normal or below normal.
While the North experiences a drier-than-normal winter, the majority of the South looks like it may see a wetter winter. Southern California, the Southwest, Gulf states and much of the East Coast are leaning toward more precipitation than normal.
What does El Niño mean?
El Niño is a weather pattern that has to do with the weakening of the trade winds over the Pacific Ocean, which leads to warm ocean waters in the eastern tropical Pacific Ocean.
The warmer ocean water then increases the potential for rainfall in areas like Southern California through Texas and even into the southeastern U.S.
In a typical El Niño winter, the Polar jet stream sets up slightly further north, which makes for warmer-than-normal temperatures in the northwestern part of the country.
A persistent Pacific jet stream sets up over the South, which brings increased rainfall for the majority of the Deep South including portions of the Southeast. The Tennessee River Valley tends to run drier-than-normal from an El Niño setup.
But El Niño’s impacts aren’t guaranteed.
“Note that a strong El Niño does not necessarily equate to strong El Niño impacts locally,” the the Climate Prediction Center said in a recent update.
Plus, it’s still very early to know what winter will look like, considering autumn just began. NOAA’s fall outlooks were also updated last week, showing a likelihood of warm weather continuing in many states for a few more months, plus rain down South.
Source : WCIA
