Sunday started off with a bit of cloud cover thanks to a few overnight showers that moved through parts of the Stateline. The cloudy start did limit how warm temperatures got during the afternoon, but a bit of late day clearing pushed temperatures into the upper 70s and low 80s. Much of Sunday afternoon and evening remained dry, but a few isolated showers/storms moved through northern Carroll, Jo Daviess and Stephenson counties.
High pressure well to our north in Canada is helping to push what is known as a ‘backdoor cold front’ down Lake Michigan and into southeast Wisconsin and northeast Illinois. It’s called a ‘backdoor cold front’ because it is coming in from the East/Northeast, rather than the West or Northwest. The front has pushed well inland, now reaching I-39 in northern Illinois and southern Wisconsin. Temperatures behind the front have fallen quickly, with the 50s now just along the lake shore and mid 60s stretching from Belvidere to Janesville. While the front won’t maintain its strength this far west, we will see temperatures fall into the low 60s and upper 50s behind the front for places from Monroe to Ridott to Rochelle, and points east. West of that line overnight lows are likely to remain in the mid 60s.
The incoming cold front may be just enough to spark off an isolated shower through this evening, as thunderstorm activity has been ongoing in southwest Wisconsin. Elevated instability does climb a little after Midnight. There will also likely be some fog that develops, especially right along the front, early Monday morning.
The chill doesn’t last as southwest winds pick up mid morning, pushing the front back to the northeast as a warm front. This will allow high temperatures on Monday to climb back into the low to mid 80s. While a few isolated showers/storms may be possible during the afternoon, much of Monday is looking to remain dry and warm.