THE WEEK ENDS on a lovely note! The day’s high comes in at 78 with dew points LOW—at 49-deg. That means the air is incredibly comfortable.  

There’s been a haziness to the sky. That’s the produce of smoke off Western U.S. and Canadian wildfires coming in aloft. The density of that smoke is to thin according to forecast models Saturday.  But just as we had a colorful sunrise thanks to the presence of the smoke aloft which screens the “blues” on the electromagnetic spectrum leaving the sunlight with a decidedly orange-hue, we should see a colorful sunset this evening and weekend sunrises and sunsets look colorful as well.

THE WEATHER LOOKS GREAT for the big weekend CHICAGO AIR & WATER SHOW.  Generous sunshine and a well developed “SSW” flow Saturday begins a day and a half of warming,  There will be NO lake cooling Saturday. It should be a great beach day with warmth extending right up to and out over the lakeshore areas. Lake water temps have been holding steady this week at season highs of 73-deg.  

An interesting twist to the weekend forecast is the arrival of a back door cold front likely to pass in the early afternoon. Back door cold fronts sweep southward over Lake Michigan ushering NE winds which have run the full length of Lake Michigan into the area. They crash temps in that manner.  Sunday’s back door front certainly fits that mold—with days likely to surge amid noticeably higher humidities into the low and mid 90s—only to dive along Lake Michigan into the 70s by evening. That’s a near 20-deg drop! 

The NNE winds that front ushers into the area are to continue Sunday night and Monday thus lowering temps—especially along Lake Michigan— even as a massive HOT AIR DOME develops aloft.  Highs Monday are likely to surge into the mid to upper 80s inland but hold to the mid 70s to near 80 along Lake Michigan.

But the restraint on warming won’t last.  And there are now indications some REAL HEAT is to build into Chicago under the hot air dome with high temps eclipsing the hottest readings we’ve see this summer to date—a high of 93.

Highs by Wednesday and Thursday now appear to likely to surge into the mid to upper 90s and may even flirt with 100-deg before a sharp cool front settles into the area and passes late next week bring a period of cooler air into the city. 

Thunderstorms may flare as that late week transition occurs.

HERE’S MY LATEST FRIDAY CHICAGO METRO FORECAST (8/18/2023):

TONIGHT: Scattered clouds, a bit smoky—but with low humidities and comfortable temps.  Low 62—mid 60s possible cooler inland locations.

SATURDAY: Mostly sunny, turning windy and warmer. Humidities will creep a bit higher later in the day.  High 86.

SATURDAY NIGHT: Scattered clouds, warm, turning hazy and more humid with steady southwest winds. Low  72.

SUNDAY: Sunshine, turning hazy, hot and humid through midday—but then winds shift “NNE” and temps drop.  Some clouds develop.  High 94—but falling sharply to the mid 70s by evening.

MONDAY: Clouds and mixed sun, hazy, warm and humid. High 86—but mid to upper 70s lakeshore.

TUESDAY: Partly sunny, hazy and humid. Temps warm. High 91—but low to mid 80s beaches.

WEDNESDAY and THURSDAY: Mostly sunny, quite hot and humid. High Wednesday 97 and 99 Thursday—but a bit lower along Lake Michigan.

FRIDAY: More clouds, humid but not as warm. Some clusters of t-storms possible.  High 86.