Big changes loom which are to bring a jarring but temporary end to the warmth we’ve enjoyed much of the past week.
Strengthening easterly winds and the chilly waters of Lake Michigan are the culprits. Longtime Chicagoans know the area is just a wind-shift away from a spring chill—and such a wind-shift looms.
Easterly lake breezes are to repeat the localized (i.e. limited coverage) cooling observed in recent days Thursday afternoon. While areas away from the lake head into the 80s for a third consecutive day, easterly winds off Lake Michigan’s chilly waters will transport cool air ashore, taking lakeshore and beach temperatures down to the 50s later today. That cooling is to become far wider in scope as easterly winds strengthen Thursday night. It’s a development destined to limit Friday highs to the 50s and 60s.
Highs here the past two days the warmest in the over 8 months since last Labor Day
Wednesday’s 84-degree high at O’Hare followed the area’s earliest 91-degree peak reading in 31 years Tuesday. Together, the past two days’ peak readings have been the warmest observed here in the more than eight months since last Labor Day weekend.
Returning warmth, surging humidities could ignite severe weather in the heretofore quiet 2013 severe weather season
The chill of coming days is to be replaced by resurgent warmth and humidity later this weekend into early next week. But with elevated temperatures and dew points on the way as part of this resurgence and a jet stream predicted to take up residence aloft in the Midwest, the stage could be set for an unwelcome awakening of the 2013 tornado and severe storm season.