Light Showers Monday:
From Friday’s significant severe weather to Saturday’s snow showers to Sunday’s sunshine, I think it’s safe to say that the northern Illinois and southern Wisconsin experienced a whirlwind of seasons this past weekend. While Monday will be a fairly quiet day overall, severe weather potential makes a quick return for Tuesday.
Mixed sunshine kicks off the work week, with clouds increasing after mid-morning. With winds being more out of the southeast, high temperatures will end up in a similar territory to Sunday, peaking in the mid to upper 50s. Eventually, the atmosphere will have enough moisture for a few scattered showers, perhaps a few isolated thunderstorms to develop, with chances lasting into the overnight hours. Thankfully, severe weather is highly unlikely. However, we cannot completely rule out a strong storm or two, especially south of Interstate 88 where the Storm Prediction Center has a Marginal Risk (level 1 of 5) in place.
Tuesday’s Severe Threat:
All eyes then will be focused on a warm front that aims to lift into northern Illinois sometime late Tuesday afternoon into Tuesday evening. Earlier this morning, the Storm Prediction Center placed our counties hugging the Mississippi River, western Illinois, eastern Iowa, northeast Missouri under a level 4 moderate risk for severe weather.
Forecast models this morning show storms initiating across northeast Missouri/southeast Iowa early Tuesday afternoon, tracking northeast into western/northwest Illinois by Tuesday evening. The one thing we’ll have to keep an eye on is the strength of what we call the “CAP”.
The “cap” is a “atmospheric lid” or a layer of warm air that sits roughly 5000 ft above the surface and more times than not gives strong thunderstorms a hard time to mature. If the holds, our threat will hold off until Tuesday night. If the cap breaks, any storms present will be able to mature, allowing all severe hazards to be possible. With less active weather slated for today, take time to update your severe weather kit and your safe place.
The associated cold front will then come through mid to late morning on Wednesday, with temperatures cooling into the upper 50s by the afternoon. High pressure then takes control of our atmosphere for the late week days, resulting in a stretch of tranquil weather. Highs Thursday will climb into the low 50s, then upper 50s for Friday.