Midweek warmth could also come with a few thunderstorms

 

Hard to believe that it was just one week ago that the snow was flying following our blizzard warnings that were in place for all of northern Illinois and southern Wisconsin. And what's even more impressive is that we had those conditions last Monday, and at the end of the week the sun was shining bright and temperatures warmed into the 70s, 80s, and even 90s in the Midwest Saturday! But a strong cold front early Sunday put an end to the warmth leaving temperatures in the 40s during the afternoon. The sun was able to return today but there was still a little chill in the air with temperatures staying in the mid 40s.

Clear skies will take us through the rest of the evening with a slow increase in cloud cover tonight. With such a dry air mass in place and a lighter wind from earlier this afternoon, temperatures are likely to drop into the 20s. Tuesday will feature filtered sunshine with highs warming into the low 50s. We'll continue the warmup Wednesday and Thursday with highs reaching the 60s Wednesday afternoon and possibly the low 70s Thursday. But Thursday's forecast comes with a few question marks. So, let's talk about that:

Low pressure moving across Iowa late Wednesday night and Thursday morning will pull a warm front just north of the state line by Thursday afternoon. South of the front temperatures will warm into the 70s and 80s while north of the front temperatures will remain in the 50s and 60s. A surge of moisture (higher dew point temperatures) will also follow the front, reaching northern Illinois during the afternoon. This will gradually lead to an increase in instability across central and some of northern Illinois. But at the same time the warm air aloft will act as a cap, or lid, for much of the day limiting the chance for thunderstorms. As the day goes on the cap may weaken, especially in central Illinois ahead of a cold front. And as of Monday evening, this is the area that has the highest chance for thunderstorms Thursday afternoon and evening.

Should the front slow down some we could see the chance for a few storms locally increase, but should it speed up then chance would be shifted even further to the south. It would also mean that our temperatures likely wouldn't reach the 70s. A brief return of cooler air will arrive Friday before we see temperatures warm once again heading into the weekend and next week.