A prolonged stretch of calm weather came to an end on Friday as showers and storms returned to the Chicago area ahead of a more active weather pattern – and a greater potential for severe weather in the following hours.
The Storm Prediction Center placed many of Chicago’s southwestern counties under a “slight” risk of severe weather, which ranks as level two of five. The rest of the Chicago area was under a “marginal” risk, which is considered level one.
A ground delay program was issued at O’Hare International Airport due to scattered storms and remained in effect for several hours before being lifted Friday evening.
Storm chances are expected to shift south in the evening, with activity likely returning by Saturday morning.
However, the greatest risk for any severe weather is overnight.
Here’s a breakdown of what to expect, when:
Overnight Friday into early Saturday
After a few scattered showers and storms move through during the evening, a stronger severe threat arrives overnight.
NBC 5 Storm Team Meteorologist Kevin Jeanes explained the greatest potential for severe weather is from 3 to 6 a.m. south of Interstate 80. Primary hazards include torrential rainfall and localized strong to damaging winds.
Hail of up to an inch is possible, and damaging wind gusts could potentially reach 60 miles per hour.
The tornado risk remains low, Jeanes said.
With all the moisture in the atmosphere, some storms could bring very heavy rainfall, leading to pockets of localized flooding.
Saturday
Storms from overnight will likely move out by the early morning, around 6 or 7 a.m., paving the way for a mostly dry day.
NBC 5 Storm Team Meteorologist Iisha Scott said rain and storm chances sit around 30%.
She explained that an isolated showers or thunderstorm can’t be ruled out in the afternoon, however. Highs are expected to reach the mid-80s.
Sunday and beyond
Sunday will start mainly dry, with most areas expected to remain dry throughout the day. Rain chances will be a little bit higher for communities to the south and southwest.
Temperatures decline slightly, with highs in the low 80s. More summer-like weather returns in the days ahead as readings in the 90s arrive next week.
