Strong Storms Possible for Wednesday

The Storm Prediction Center has placed most of Northern Illinois and Southern Wisconsin under an 'Enhanced Risk' for severe weather for Wednesday.  If everything comes together, Wednesday could potentially be a dangerous day.

However, before we get too excited about that potential it's important to look at the features in the atmosphere giving us that threat.

Monday's high temperature reached 92 degrees, a hot one!  But a cold front has passed bringing an end to some of the higher humidity.  That front will stall to the south Monday night and Tuesday, but be pulled back north as a warm front Tuesday night and Wednesday morning.

As we get further and further into the summer months, storm systems known as MCSs (Mesoscale Convective Systems) become more common.  The warm front may become a little more defined to the south near the Missouri/Iowa/West-Central Illinois borders.  As the low level jet (strong winds in the lower part of the atmosphere) increase Tuesday evening and Tuesday night, a warm and moist air mass will pulled towards the front.  This will occur at the same time stronger winds within the atmosphere will be moving over the Upper Midwest.  Thunderstorms will likely develop over northern Iowa Tuesday evening as move southeast along the warm front Tuesday night into Wednesday morning.  It's possible that these storms form into an MCS when reaching southern Wisconsin and northern Illinois Wednesday.  If so, a high wind and heavy rain threat would occur early Wednesday. 

The afternoon is where it gets interesting.  If this storm complex does occur and is quick to leave allowing our atmosphere time to destabilize during the day, the warm front that was to the south Wednesday morning would then become the focus point for additional thunderstorms (some likely severe) by late afternoon and evening.  These, too, would pose a high wind threat, but also a slight tornado risk initially.

I believe thunderstorms during the morning Wednesday are a very good bet, with the afternoon depending heavily on what happens during the morning.  Stay weather aware the next couple of days and we'll continue with the updates right here!  Another threat will be the possibility of flash flooding due to the extreme amounts of moisture we will have in the atmosphere.  Wherever the warm front ends up will allow thunderstorms to continuously move over the same areas.  Definitely something to watch as well.