Active weather set to move into the Stateline

As we fall further and further into the spring and summer months thunderstorm complexes known as MCS's (Mesoscale Convective Systems) become more likely.  Simply put, an MCS is a cluster - or complex - of thunderstorms that move through during the overnight and are typically heavy rain and wind producers.  With a ridge of high pressure building across the Plains we'll remain along the outer edge of the ridge leaving us in the prime spot for these storms to move through with the first one affecting us tonight.

Low pressure developing in the central Plains today will push a warm front closer to Northern Illinois this evening.  While most will remain dry this afternoon an isolated thunderstorm or two can't be ruled out.  Of greater concern will be the storms that develop out west across parts of Iowa and Minnesota later today.  Those storms, if they hold together long enough, will follow the flow within the jet stream and move in our direction late tonight/early Wednesday morning.  This complex of storms will likely be in a 'decaying' stage but a few stronger wind gusts and bouts of heavier rain will be possible.  The warm front will remain draped across the Wisconsin/Illinois state line Wednesday afternoon.  A very warm and humid air mass will develop south of the front while a cooler and drier air mass will be in place north of the front.  A strong upper level low will move out of the southern Rockies tonight and lift towards Iowa and Northern Illinois by late afternoon Wednesday.  With an already unstable air mass in place thunderstorms will likely redevelop late Wednesday afternoon and evening.  Severe storms are possible with wind and hail being the primary threats and heavy rain becoming a second concern.  Rainfall amounts of 1"-2" will be possible by Thursday morning.  Northern Illinois and Southern Wisconsin have been placed under a slight risk for later today, tonight and Wednesday.  Once this system passes the weather will turn quiet Thursday and Friday but pick back up Saturday and Sunday.  Be sure to keep up-to-date with the latest forecasts as severe weather is possible Wednesday.