Multiple rounds of storms, some severe, expected to sweep across northern Illinois

Mother nature gave us a beautiful and problem-free weekend as Saturday and Sunday featured sunshine with highs spread out in the 80s. 

This kind of summer-like warmth continues into the start of the new work week. However, it does come with a bit more humidity, allowing storm and even severe potential to make a quick return. 

Monday's will come in two rounds. One that is passing to our west and northwest as we speak, with chances lasting into sunrise. These have been sliding through in a non-severe fashion and will continue to do so as they move through S. Wisconsin. Timing of the second round seems to be from 10AM to 3-4PM. Now, it goes without saying that the severity of this round will all be dependent on how much atmospheric energy will be available. If storms are to meet severe criteria, it would be for damaging winds and large hail. Today's storm threat would diminish before sunset, leaving us quiet for the first half of the night.

In a similar fashion to today, Tuesday's potential also comes in two rounds. One early in the morning and another later in the evening. Storm mode would be in the form of a line or complex of storms, with the main question marks there being the inefficient timing outside of peak daytime heating.

 

 

The first round would arrive after midnight, with chances lasting into sunrise. Damaging winds and heavy rain would be the biggest concerns. Conditions quiet down from there, allowing temperatures and dew points to climb quickly. 

Highs for most will reach the upper 80s, with maybe a spot or two briefly touching the 90° mark. At the same time, storms firing to the west will congeal into a strong squall line, progressing east with time. 

If there are any outflow boundaries laying around from the morning round of storms, that would further out chances for afternoon severe storms. Otherwise, it's this line that will bring the potential for damaging winds, large hail, and a few tornadoes during the evening and early overnight hours Tuesday. Again, all dependent on the amount of instability that builds up ahead of this potent line. But for tomorrow's heightened threat, the Storm Prediction Center has placed the entire region under a level 3 of 5 enhanced risk for severe weather.

Any chance for strong to severe storms will come to a close after the associated cold front slides through. This will be sometime around midnight or the early morning hours Wednesday. 

The rest of Wednesday and all of Thursday remain quiet, with temperatures peaking in the 70s. It won't be until late Friday where rain and even thunderstorm chances return to the Stateline.