The upper air flow is going through a significant pattern change that will result in warm, very humid air spreading over the Chicago area during the next few days — and ultimately a good chance for strong thunderstorms with heavy rains and potential severe weather early next week.
Sunny days coming up
Friday and Saturday will see plenty of sunshine – allowing temperatures to return to slightly above seasonal averages (normal high 84-degrees). Light southerly winds will carry more humid air into the area with dew-points rising through the 60s into the lower 70s later in the weekend. Scattered cumulus clouds will build through the afternoon – perhaps resulting in a few isolated late-day and early evening thunderstorms over about 20 percent of the area.
Strong storms early next week
With a west-east jet stream aloft just to our north, warm very humid air in place here, and a cold front approaching from the northwest, northern Illinois will be in perfect position for strong thunderstorm activity – beginning late this coming Sunday and continuing into mid-week.
