Isolated thunderstorms late Wednesday fueled by summer-like heat

 

For the first time since mid-May afternoon temperatures warmed into the low 90s. Rockford's high reached 91 degrees. The last time the high temperature reached the 90s was back on May 15th when we recorded a new record high temperature of 94. The heat came in full force Wednesday afternoon, but the humidity remained in check - for now. Through the night dew point temperatures will begin to rise which will bring back some of the higher humidity overnight and into Thursday.

Severe thunderstorms have been ongoing in northern Iowa along and ahead of a cold front that sits right along the state line Wednesday evening. This boundary will serve as the focal point for storms to continue to develop and move along over the next few hours. There have been a few clouds locally that have started to bubble up but haven't really grown much over the last couple of hours.

The storms now near Waterloo, IA will continue moving east, although a slight dip to the southeast may occur. The highest coverage of scattered storm activity will likely remain from northeast Iowa into southwest and southern Wisconsin, but an isolated storm or two may sneak south of the state line and move across far northern Illinois.

If this occurs there is still a low-end risk for a storm to reach severe limits producing gusty winds. A 'slight risk' for severe storms was added to include northern Iowa and southwest Wisconsin, while the 'marginal risk' was trimmed back just a bit including southern and southwest Wisconsin and far northwest Illinois.

These storms will continue to mainly move from west to east through the night and into Thursday morning. As the front sinks a little further south through sunrise it'll once again be pulled back north through Thursday afternoon which will bring afternoon temperatures back into the 80s. This time, however, dew points will be on the rise which will give the afternoon a little more of a muggy feel.

The heating of the day combined with any lingering boundaries may be enough to fire off an isolated storm or two mid to late afternoon Thursday. By Thursday night winds will turn back to the northeast as a lake enhanced front pushes further inland. The same will occur for Friday as winds turn back south bringing temperatures into the 80s. An upper-level low currently over the southern Plains will open into more of a wave (trough), lifting into southern Illinois Friday afternoon. This will help drive scattered showers and thunderstorms to the south, while another disturbance moves to the north. We may once again see an isolated storm or two Friday afternoon and evening, but overall coverage is expected to remain limited.