Winter Outlook Update: Warm Conditions Expected In The Northern Tier

Winter in the United States could have the signature of El Niño's influence, according to an outlook released Thursday by The Weather Company, an IBM Business, and Atmospheric G2.

Warm conditions expected in parts of the Northern Tier: A strong El Niño is favored this winter, which is typically associated with warmer-than-average conditions in much of the northern U.S. It also means parts of the southern U.S. usually see temperatures somewhat below average in winter.

T​hat temperature pattern is generally the theme of this winter's outlook in the map below.

This outlook is an overall three-month trend, so there will be periods that are warmer or colder in each respective region of the country when compared to what is shown above.

W​ith that in mind, let's break the forecast down month-by-month and follow up with some important factors that could change this outlook.

W​inter could begin warmer than average in the Great Lakes, Northeast and mid-Atlantic: Those in the northeastern U.S. wishing for a cold December to set the mood for the holiday season might be out of luck this year. Cities like Washington, Philadelphia, Chicago, Boston and New York City all are currently favored to have temperatures the farthest above average in December.

T​he western U.S. into the Southeast should see temperatures pretty close to what's typical.

The Southeast could skew somewhat colder to start the new year: A hallmark of El Niño is cool, wet conditions in parts of the southern states in the heart of winter, and that's what the outlook is showing from the lower Mississippi Valley to Georgia and parts of the mid-Atlantic. It's not a guarantee, but that combination of ingredients could increase the chances of snow and ice in portions of this region.

P​arts of the West into the Northern Plains and Northeast have the highest odds for above-average temperatures in January.

W​inter's final full month could feature a colder East, warmer West and Plains: In February, the core of the warmest temperatures compared to average could be from the Northwest into the Northern Plains.

Much of the East, however, could skew colder than usual, with t​he best chance for colder-than-average temperatures in Florida and south Georgia.

These F​actors Could Change The Winter Forecast

How much of an atmospheric response will there be to El Niño's warm Pacific waters?: The current lack of atmospheric response we've seen in the tropical Pacific means that Arctic air intrusions could be more common in comparison to typical strong El Nino winters, according to Dr. Todd Crawford, Vice President of Meteorology at Atmospheric G2.

Will the polar vortex weaken later in winter? When the polar vortex weakens, the cold air typically trapped in the Arctic can spill out into parts of Canada, the U.S., Asia and Europe because the jet stream becomes more blocked with sharp, southward meanders, sending more persistent cold air southward toward the mid-latitudes.

C​rawford said there is a very good chance the polar vortex could weaken in mid-winter, which means there are colder risks in the U.S. during the back half of winter.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.