Midweek Storm to Bring Rain, Storms and Wind to the Midwest

Two storm systems will impact the Great Lakes this week.  The first arrives Monday afternoon and evening, having very little influence on our weather.  The second, and stronger, system will have a much larger impact on the weather in Northern Illinois and Southern Wisconsin.

Let's first talk about the first system:  Low pressure in the Southern Plains.  An upper level low spins through Kansas and Oklahoma Sunday evening with very little reflection at the surface.  This low will move northeast into Illinois, Indiana and Ohio by Tuesday morning.  But because our atmosphere is very dry, we will likely only see an increase in cloud cover by Monday afternoon.  Any rain that does fall with this low should remain east towards Indiana and Ohio.

The second, and larger, storm system currently sits off the coast of the Pacific Northwest.  This storm will have a greater impact on a larger portion of the country.  Bringing snow out west and potentially severe weather as close as the Quad Cities and Peoria Wednesday afternoon.

As surface low pressure develops east of the Rockies Monday and Tuesday, gulf moisture will be pulled northward into the Central and Southern Plains.  This gulf moisture will interact with very strong winds in the jet stream likely producing thunderstorms, some severe, from Nebraska, Kansas, Missouri and Iowa Tuesday afternoon and evening.  Between Tuesday and Thursday, that low pressure will quickly intensify as it lifts northeast from the Plains into Wisconsin by Thursday morning.

This will draw the gulf moisture even further north by Wednesday evening into Illinois, and possibly southern Wisconsin.  Rain will begin to fall by Wednesday afternoon with thunderstorms possible Wednesday evening.  With such strong dynamics in the jet stream and strong winds both aloft and at the surface, strong to severe thunderstorms can't be ruled out for Central and Southern Illinois Wednesday afternoon.  We could even have a few stronger storm in Northern Illinois by Wednesday evening.  Something the First Warn Weather Team will be watching very closely the next couple of days!  The

Storm Prediction Center
Day 4 Outlook

Storm Prediction Center is already highlighting Central and Southern Illinois as an area of interest Wednesday afternoon.

The warm front associated with the low will lift north through Rockford Wednesday night, keeping temperatures very mild into the wee hours of Thursday morning.  A cold front will be quick to pass, however, Thursday morning bringing temperatures down into the 40's by Thursday afternoon.

Surface winds will also increase significantly Wednesday night and Thursday morning with wind gusts possibly reaching 40mph.  A second shot of cold air slides down Friday morning with highs Friday afternoon not making it much past the low 40's.  There could even be a few showers Friday morning!