Winter Weather Outlook: Possible El Niño Influence

The upcoming winter season in the United States may bear the hallmark of El Niño’s influence, as indicated in a recent forecast from The Weather Company, an IBM Business, and Atmospheric G2.

This influence is discernible in the comprehensive three-month winter outlook. The forecast suggests that a robust El Niño is anticipated for this winter, a phenomenon typically linked to above-average temperatures in much of the northern United States. In contrast, it often results in slightly below-average temperatures in parts of the southern U.S.

However, it’s important to note that this outlook provides a broad three-month trend, so there could be periods of both warmer and colder weather in specific regions compared to the general forecast.

Month-by-Month Projections

Let’s delve into the month-by-month projections for this upcoming winter and examine some key factors that might alter this outlook.

December: Winter could kick off with unseasonably warm conditions in the Northern Plains, Great Lakes, and Northeast. If you were hoping for a chilly December to set the holiday mood, you might be in for disappointment. Cities like Minneapolis, Chicago, Boston, and New York City are all expected to experience temperatures significantly above average. Meanwhile, the southern tier of the U.S. is likely to see temperatures close to the seasonal norm.

January:As the new year begins, the southern U.S. might experience slightly colder-than-average temperatures. A typical feature of El Niño is cool and wet conditions in parts of the southern states during the heart of winter, and this outlook suggests that from the Southern Plains to Georgia and the Carolinas, there’s a possibility of increased chances for snow and ice. On the other hand, parts of the Northwest and Northeast have the highest likelihood of experiencing above-average temperatures in January.

February:The last full month of winter may bring a split in temperature trends. In February, the warmest temperatures compared to the seasonal average could prevail in the Northwest and northern Rockies. Conversely, the Southeast to the mid-Atlantic might have a higher chance of encountering colder-than-average temperatures.

Factors that Could Alter the Winter ForecasT

Several critical factors could potentially modify the winter forecast.

1. Atmospheric Response to El Niño:The extent of the atmospheric response to El Niño’s warm Pacific waters plays a pivotal role. According to Dr. Todd Crawford, Vice President of Meteorology at Atmospheric G2, the current atmospheric conditions resemble those of the 2009-10 El Niño, which was characterized by cooler temperatures in the central and eastern U.S. Therefore, close monitoring of trends in the coming weeks and months is necessary to determine the extent of El Niño’s influence on winter weather patterns and whether the outlook may shift towards cooler conditions.
2. Polar Vortex Strength:The weakening of the polar vortex later in the winter can have significant implications for weather patterns. When the polar vortex weakens, the frigid air typically trapped in the Arctic can spill into parts of Canada, the U.S., Asia, and Europe. This happens because the jet stream becomes more blocked with sharp, southward meanders, redirecting cold air toward lower latitudes. Dr. Crawford suggests a good chance of a mid-winter weakening of the polar vortex, which could lead to colder conditions during the latter part of winter.
3. Global Warming Influence:The recent surge in global warmth is another factor to consider. As of the end of September, the Earth was on track to experience its warmest year on record. Dr. Crawford notes that this additional burst of global warmth in 2023 may result in an upward shift in temperatures. In practical terms, this means that warm periods could be even warmer than usual, while cold periods may be less severe than typical.

While the winter outlook suggests an influence of El Niño with a predisposition towards warmer conditions in the northern U.S. and cooler conditions in the southern U.S., these projections are subject to modification based on the evolving interplay of these significant factors. Therefore, as winter approaches, we must remain vigilant and adaptable in our preparations for the upcoming season.