If you haven’t read through Chief Meteorologist Eric Sorensen’s Tuesday blog post regarding our severe weather threat for Wednesday afternoon, I’d recommend it. You can find his blog post HERE.
A somewhat stable airmass is in place across the Stateline for Wednesday morning. Overnight showers and thunderstorms in western Iowa fizzled out before they crossed the Mississippi River into Illinois. The result is a mostly cloudy morning with a few breaks of sunshine. Humidity and temperatures will be on the rise throughout the day, with highs expected to reach the middle 80s.
The meteorological ‘ingredients,’ so to speak, are coming together for severe weather later today. With a surface wind still expected out of the southeast and an upper-atmospheric wind out of the south-southwest, directional wind shear and storm rotation will be a concern this afternoon and evening. A warm front is still expected to lift into northern Illinois this afternoon, at least as far north as the Interstate 88 corridor. It is along this front that supercell thunderstorms may develop. Supercell thunderstorms have the potential to produce strong wind gusts, large damaging hail, and possibly a tornado. These threats will all be of local concern this afternoon, including torrential rain.
Don’t panic. However, today is a good day to be ‘weather aware’ and keep an ‘eye on the sky.’ Make sure you have a severe weather safety plan in place. We haven’t seen a threat like this across the Stateline for a few years. Let’s plan for the worst and hope for the best.
As far as timing goes, our array of forecasting products are not on the exact same page. However, the best timeframe for severe thunderstorms to develop is this afternoon and evening. Storms may begin to form in eastern Iowa around 2pm through 4pm and move east-southeast into our area after that. Some model solutions begin a bit earlier, some begin later around dinner time. We do know that this afternoon and evening will be active.
Don’t forget, you can track the storms on your smart phone with our 13 Weather Authority App or sign up for severe weather text alerts.
This post was written by Joe Astolfi on June 12, 2013