Storm chances tag along with this weekend's heat and humidity

Thursday's rainfall has left behind some moisture near the surface, hence the fog that is developing ahead of the morning commute.If you plan to travel, take it slow as visibility will fluctuate. 

Once the fog lets up, we're in for another quick warm up as a warm front lifts through during the mid-day hours.This will likely place temperatures in the low 90s for the seventh time this year, 3 more than the average between May and June. 

As we've seen on countless occasions this week, this heat will come with high humidity, leaving heat indices in the mid to possibly upper 90s.  

It's during this time in which forecast models do show a round of thunderstorms developing along said warm front north of the IL/WI border. With time, these will sink east-southeast, possibly bringing those in extreme N. Illinois an isolated thunderstorm chance during the evening. Temperatures remain warm overnight, landing in the low 70s. In their latest severe outlook, the Storm Prediction Center does have the marginal risk extending down to highway 20. If any storm were to remain severe, gusty winds and hail would be the primary concerns. 

Severe chances go up Saturday afternoon and evening as an area of low pressure helps bring a cold front in from the west and northwest. Areas west of Genoa, Rochelle, and Amboy have been placed under a level 2 of 5 Slight Risk for severe weather. 

Included is the risk for damaging winds, large hail, and a tornado or two cannot be ruled out. I believe the tornado threat is higher to the west where storms may have a better shot at staying isolated. Though this cold front won't have much cool air behind it, it will be enough to give us a brief break from the high heat and humidity. Highs will fall from the low 90s Saturday afternoon to the mid 80s Sunday afternoon.