It was markedly chillier today than Thursday with a high of just 45-deg — a reading 6 degrees below normal and cool enough to rank among Fall 2023’s  season’s four coolest days.

Clouds will break up as expeditiously tonight as they arrived Friday.  While the day opened sunny Friday morning, an overcast spread in during the late morning and afternoon.

The clearing is to permit temps to drop in the chilly Canadian air mass which has swept in across the area.  That diminishing winds and 20-deg dew points will be present tonight—an indication of an environment in which all the stops to slow nighttime cooling are being removed–it’s likely we’ll see some bone-chilling mid 20-deg lows in the normally colder locations which surround the city and are away from the warming influence of Lake Michigan with its low 50-deg water temps. 

Speaking of Lake Michigan, its water temps off Chicago have dropped more than 20-degrees off their late August high of 72.4-deg—having settled to an average of 52.3-deg Friday over the south end of the lake.  The U.S. Army Corps of Engineers Great Lakes water level report issued each Friday is in and shows Lake Michigan’s water level has dropped 2″ below the level observed on this date a year ago. That report also reveals Lake Michigan’s water level is now just 5″ above the long term average for November.

Also on the subject of the Great Lakes—-today marks the 48th anniversary of the tragic sinking of the SS Edmund Fitzgerald in eastern Lake Superior—the largest of the 6,000  Great Lakes ships which met their demise on the challenging water bodies.  It sank in a monster autumn storm which computer simulations performed since the sinking Nov 10, 1975 indicate the ship indicate sustained winds of 55 mph with hurricane force 80 to 85 mph winds were in progress when the ship disappeared beneath the cold, wind-whipped waters of Lake Superior.  It took 4 days for Navy and Coast Guard search effort to locate its remains in two large pieces beneath more than 500 ft of water there.  Tragically, the Fitzgerald’s crew of 29 perished in the sinking.

A chill holds through Saturday with another day in which high temps will struggle to approach 50-deg are predicted.  But while 30s are forecast Saturday night across the Chicago area, Pacific air will begin to return Sunday boosting afternoon temps nearly 10-deg higher than the 49 predicted Saturday.

And that warming trend is to dominate the weather scene here next week with high temps by mid-week (Wed & Thu likely to reach the mid 60s—64 and 65-deg Wed/Thu respectively.

Precip will be in short supply. Only Thursday night appear likely to see some showers in Chicago next week.  

Things may get wetter and on a larger scale later next weekend going into the following week and, while an average of temp forecasts of a suite of different computer models has readings dropping off more than 6-deg on average the following week (though still averaging above normal in the week following next)–there are some models suggest ridging aloft over western North America may set the stage for more aggressive cooling as air spills into the Midwest from Canada.  That’s a development worth monitoring—and we’ll be doing just that.  But that would occur beyond next week—so we have time to monitor future forecast developments.


TONIGHT: Clouds scattering and diminishing. Initially gusty winds will ease significantly allow colder air to settle in. Low 30 in the city—but low to mid 20s coldest inland areas. 

SATURDAY: A sunny open—but some clouds gather again in the afternoon and evening. Chilly. High 49.

SATURDAY NIGHT: Mostly cloudy and chilly. Low 38—but low 30s inland.

SUNDAY: Clouds break—turning mostly sunny, breezy from the south and milder. High 58—9-deg warmer than Saturday.

MONDAY, TUESDAY AND WEDNESDAY: Generous sunshine, milder—especially Tuesday and Wednesday.  Highs 60 Monday; 62 Tuesday and 64 Wednesday.

THURSDAY: Increasing cloudiness, windy and mild. Nighttime showers likely. High 65.

FRIDAY: Mostly sunny, breezy and a little cooler—though still mild for the season. High 60.