- The El Niño phenomenon is expected to play a role in affecting winter temperatures.
- This typically means milder winters in the northern United States, and cooler and wetter conditions in parts of the south.
- But there are some important factors that can change the winter forecast.
A U.S. winter could bring an El Niño effect, according to a forecast published Thursday by The Weather Company, an IBM Business division, and Atmospheric G2.
Warm weather is expected in parts of the northern layer: A strong El Niño is likely this winter, which is typically associated with warmer-than-average conditions across much of the northern United States, and also means that parts of the southern United States typically see somewhat lower-than-average temperatures in the winter.
This temperature pattern is generally the subject of the forecast for this winter in the map below.
The temperature pattern that is expected to dominate the entire three-month period from December through February.
This forecast is a general three-month trend, so there will be warmer or cooler periods in each region of the country than shown above.
With that in mind, let's break down the forecast month by month and go over some important factors that could change these forecasts.
Winter could start off warmer than average in the Great Lakes, Northeast, and Mid-Atlantic: Those in the Northeastern United States who want cool December weather to set the mood for the holiday season may be out of luck this year. Temperatures in cities like Washington, Philadelphia, Chicago, Boston, and New York are currently expected to be above average in December.
The western United States to the southeast should see temperatures very close to normal.
(Enhance your forecasts with our hour-by-hour breakdown for the next eight days – available only on our website.) Premium Pro experience.)
Temperature forecast for December.
The Southeast may tend to get somewhat colder as the new year begins: The hallmark of El Niño is cold, wet conditions in parts of the southern states in the heart of winter, as forecasts show from the lower Mississippi Valley to Georgia and parts of the mid-Atlantic. It's not a guarantee, but this combination of ingredients could increase the chances of snow and ice in parts of this area.
Parts of the west to northern Plains and northeast have the highest potential for above-average temperatures in January.
Temperature forecast for January.
The last full month of winter can feature the colder east and warmer west and plains: In February, the warmest temperatures compared to average can be centered from the northwest to the northern plains.
However, much of the East may tend to be colder than normal, with the best chance for cooler-than-average temperatures in Florida and southern Georgia.
Temperature forecast for February.
These factors can change the winter forecast
How large is the atmospheric response to warm El Niño waters in the Pacific Ocean? The current lack of atmospheric response seen in the tropical Pacific means that Arctic air infiltration could be more common compared to typical strong El Nino winters, according to Dr. Todd Crawford, deputy chief meteorologist at Atmospheric G2.
Will the polar vortex weaken later in the winter? When the polar vortex weakens, cold air normally confined to the Arctic can spread to parts of Canada, the United States, Asia and Europe as the jet stream becomes more obstructed by steep southward swerves, sending more persistent cold air south toward the mid-Arctic. -latitudes.
Crawford said there's a very good chance the polar vortex will weaken in midwinter, meaning there's a risk of colder weather in the U.S. during the back half of winter.
An example of a weak polar vortex in winter.
The Weather Company's primary journalistic mission is to report on breaking weather news, the environment, and the importance of science in our lives. This story does not necessarily represent the position of our parent company, IBM.
