Chicago weather: Muggy, stormy pattern continues into mid-week

CHICAGO - Chicago is gearing up for a stretch of hot and very humid days. 

Highs will reach the low 90s Sunday with scattered showers and more thunderstorm potential in the evening. The peak heat index will be 100 to 105 degrees. 

A Severe Thunderstorm Warning was later issued for several counties in Northwest Indiana. Porter County, Lake County, Newton County, and Jasper County were placed under a warning until 10:30 a.m. 

Shortly before, a storm rolled through parts of Will County with 70 mph wind gusts and pea-sized hail. 

Monday will be even steamier with a peak heat index of 100 to 110 degrees. The National Weather Service is warning of dangerous heat. 

There's a threat of damaging winds and flash flooding through Tuesday as waves of storms continue to pass through the region.