The late season heat is on! With just seven 90s on the books officially at O’Hare to date (11 at Midway) this year, this final week of August and meteorological summer seems destined to add to the tally with a 92 Monday and 90s again Tuesday–and no lake cooling.
A 96 degree Tuesday would be the hottest late season (final week of August/first week of Sept) temperature to reach Chicago in 22 years–and it seems to be where we’re headed.
Some blockbuster late season thunderstorms may erupt Tuesday and Tuesday night across sections of Wisconsin, Michigan’s UP and Minnesota–and there are signs some of these storms may have to be monitored Tuesday night. They could conceivably impact northern sections of the greater Chicago area. Warm air capping to the south should limit the southward spread of these storms–but extreme northern Illinois is close enough to monitor this set up carefully. If nothing else, we may see quite a lightning display on the northern horizon from Chicago and our northern suburbs Tuesday night.
As of now, there’s huge model disparities over the upcoming Labor Day weekend’s weather. The Weather Service’s GFS model drives blazing late-summer heat back into the area; the European Center’s model suggests the hot dome will collapse Sunday with Canadian air washing into the area Sunday and Labor Day. The Navy model adopts aspects of each, bringing heat back Saturday but shifting winds off Lake Michigan and cooling us Sunday/Monday.