Severe weather risk for Northern Illinois on Tuesday

 After a sunny and mild Sunday, temperatures will take another jump in the upward direction for Monday, as afternoon highs push near 70 degrees for some! Record warmth is possible, given Rockford's standing record for Monday is 68° set in 2021.

It will be another mild day for most on Tuesday, but there will be big changes on the way. A warm front will set up near Northern Illinois, which could be the focal point for severe thunderstorms, including tornadoes Tuesday afternoon and evening. Very moist and unstable air will be South of the front, with dew point temperatures above 60°. North of that front, much drier and stable air will be found.

That axis of moisture also sets up where the best instability, or storm energy, will be for severe weather will be. The highest instability will also be found across Central Illinois where the abundant low-level moisture is found. Another ingredient for severe weather is wind shear, particularly in the lowest levels to fuel a tornado risk. That will be centered nearest the warm front, likely stalling out near or just South of I-80. Storms that form North of the front will become elevated, limiting tornado risk but enhancing large hail and flooding concerns.

As of now, the primary threat for tornadic storms on Tuesday will be centered near and South of the front, which looks to set up near or just South of I-80. North of the front, severe weather is still possible, but the main threats there will be damaging hail and flash flooding. The latest severe weather outlook as of Sunday afternoon shows the Level 3/5 Enhanced Risk across much of Central Illinois where the better ingredients will be found, including the warm front itself. The Level 2/5 Slight Risk extends about to the IL/WI state line, primarily highlighting the concern for large hail. Further updates on this outlook and the forecast will come, so stay tuned and remain weather aware this week!