With the upper jet stream flow pattern favoring the advance of warm humid air from the south and west into northern Illinois, temperatures are expected to climb through the 80s into the 90s today. The air mass will carry dew points in the lower 70s which when combined with the season’s first official 90° high could result in a triple-digit heat index. A pocket of unstable air prompted a severe thunderstorm watch just to Chicago’s west and north yesterday and produced scattered t-storms a few of which brought damaging winds and 3/4-inch hail. Weakened storms passed through Chicago, and the weather system is moving east into Lower Michigan today.
An upper air pattern shift is forecast mid-week with a cold front expected to produce a period of potentially severe t-storms and heavy rains. Subsequent northerly flow out of Canada will usher in significantly cooler and less humid air to NE Illinois the latter half of this week.
-Paul Dailey, WGN-TV Meteorologist
WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.
