Smoky skies have filtered the sun and produced an orangish cast to the sky over Chicago Wednesday. The day’s high temp of 78 is about “on the money” for this time of year when the normal Sept 15 high here is 76. Despite the warmth, atmospheric moisture levels remain comparatively low which allows temps to tail off once the sun sets. This means cool, comfortable nights follow warm daytime temps. But there’s another effect. The nighttime cooling allows patchy fog formation—as happened Wed morning and may again occur Wed night/Thu morning.

Modeling continues to keep temps WELL ABOVE NORMAL THROUGH MID NEXT WEEK with daily average temps from Friday through next Wednesday to come in 10-15-deg above normal.

What has changed a bit is the expectation a weak, wind shifting front will sag southward across the area Sunday night. This is to turn winds off the lake–though lightly Monday. Still, that’s to be enough to restrain warming a bit, particularly lakeside areas Monday.

A better organized SSW wind Tuesday and the continued prediction of an unseasonably warm dome of late Sept air may allow the 90-deg temp expected Sunday and Monday—to still occur Tuesday and Wednesday next week.

There is the official astronomical start to fall next Thursday evening at 8:04 pm may be accompanied by a cool push which is to have a more autumn-like fell to it than the temps predicted between now and then.
TROPICAL SYSTEM DUE TO REACH TROPICAL STORM STATUS AS IT CHURNS WEST TOWARD THE NORTHERN LEEWARD ISLANDS, PUERTO RICO AND HISPANOLA is to encounter intensification-thwarting wind shear. Thus, at this point, it appears its major impact to the Eastern Caribbean islands may be squally rains, says the National Hurricane Center.