Rounds of everything from rain and sleet to snow this week in parts of Illinois could be the start of a more active weather pattern.
Trent Ford, state climatologist with the Illinois State Water Survey, discussed the latest outlook Dec. 29.
“We expect January and February to be much more active, weather-wise, than November and December,” Ford told FarmWeek.
“We’re starting to see signals of La Nina taking hold (of the precipitation pattern),” he noted. “The outlook calls for slightly to strongly elevated odds of wetter-than-normal conditions, particularly south and east.”
The key component to determine what form of precipitation Illinois receives the next few months obviously centers on the temperature pattern.
“Short term, there’s an elevated chance of above-average temperatures,” Ford said. “But we’re seeing some signals of changes in the arctic, with the potential for a few cold air outbreaks.”
This follows what turned out to be a generally mild year in 2020 that ended with a snowfall deficit for the first month of winter, except for the northwest corner of Illinois, prior to the month-end storms.
Statewide, the temperature averaged 1.5 degrees above average from January through November, which was the 23rd warmest on record for that stretch. The temperature departure in December was about 2 to 3 degrees above average in much of southern Illinois and up to 5 to 6 degrees above average in central and northern portions of the state.
Meanwhile, much of the northern two-thirds of the state was in a snowfall deficit of 2 to 10 inches Dec. 29, just as a winter storm approached the northwest section of the state. In Jacksonville (Morgan County), there was no measurable snowfall for the season as of Dec. 29, which was the latest without recording a measurable snowfall there since 1948.
“The outlook has been pretty boring (so far this winter),” Ford said. “But we’re starting to see a little pattern change.
“That’s mixed news, depending on where you are,” he noted. “In central Illinois, we need the water to recharge soils. But, in southern Illinois, that could mean some flooding issues come late winter and early spring.”