New forecast predictions indicate a shift could be in store for December in the Chicago area.
According to the NBC 5 Storm Team, “long range forecast models are indicating a strengthening ‘ridge’ in the jet stream as we go into the second week of December.”
“This would favor a drier and more mild pattern for Chicago,” said meteorologist Kevin Jeanes, noting that the trend could continue into mid-December.
What will happen for the end of the month, however, remains to be seen.
The shift isn’t unexpected, given that an El Niño is present and is expected to continue through winter. The stronger the El Niño becomes, the more likely it is that the Chicago area ends up with a drier and milder winter overall, Jeanes said.
Currently it’s the strongest El Niño seen since the winter of 2015-16, which was one of the strongest on record.
Between Dec. 2015 and Feb. 2016, the Chicago area received 16.5” of snow. Temperatures were also well-above normal. December of that year was especially warm, reaching 8.5 degrees above normal.
An El Niño weather pattern originates in the Pacific Ocean, and occurs when water temperatures near the equator rise above average. This is due to a shift in trade winds, which in turn change the currents within the oceans.
When the water is warm, it can alter the position of the jet stream across the globe.
If the area continues to see a strong El Niño, a drier, milder winter, is likely.
A moderate El Niño doesn’t have quite the same punch, however. If El Niño is more moderate, it could increase the potential for more snowfall, and perhaps some cooler temperatures.
As of the latest update on Nov. 9, the National Oceanic and Atmospheric Administration reported an El Niño could continue even into spring 2024.
“Based on latest forecasts, there is a greater than 55% chance of at least a ‘strong’ El Niño persisting through January-March 2024,” the NOAA reported.
There is also a 35% chance an “historically strong” El Niño could emerge.
The Climate Prediction Center is expected to release another El Niño update on Dec. 14, which will offer a closer look at the conditions expected.