FIRST, THURSDAY WEATHER HEADLINES

–The week’s SECOND OFFICIAL 70-deg HIGH TEMP today (Thursday)–the 73-deg high came within 2 degrees of the 1987 record of 75 set 35 years ago. It’s a LATE SEPTEMBER LEVEL DAYTIME HIGH.

–Tonight’s low temp—expected to straddle 60-deg in the city—is warmer than the NORMAL HIGH TEMP this time of year and could establish a new RECORD LOW MIN TEMP RECORD—coming in above the old record high min of 59 also set in 1975.

–High temps the opening 3 days of November look to average 4th warmest of the past 151 years—so the new month is off to an unseasonably warm start!

–While last week averaged 4-deg above normal, this week is to average 11-deg above normal by the time the books close at midnight Sat night.

–An autumn storm is developing between cold air, diving southward through the Western States and prompting forecasts of accumulating snow as far south as the mountains near Los Angeles, and our unseasonably warm air which has put high temp records in jeopardy across 5 Midwest states Thursday.

–The storm will race northeastward passing west of Chicago and keeping the city in its warm air sector.

–Scattered showers sweep on Friday impacting half the metro area—and up to 90% of the area Friday night and Saturday morning.

–DON’T BE SURPRISED TO SEE WIND ADVISORIES OR WARNINGS ISSUED FOR SATURDAY. While gusty south winds will top 30 mph Friday and will remain elevated, average 14 to 28 mph Friday night, it’s Saturday afternoon when a CLASSIC HIGH WIND SET-UP sweeps into the area. Powerhouse southwest winds reaching from the surface into the jet stream aloft set the stage for strong and potential damaging wind gusts topping 50 mph “mixing down” to the surface. A few spots could set gusts as high as 60 mph Saturday afternoon.

–Morning rains will give way to afternoon sunshine Saturday as the autumn storms DRY SLOT—an intrusion of dry air which shuts down precip and produces clearing—sweeps into the area in the afternoon.  DRY SLOTS in storms like Saturday’s occur beneath the strongest winds in the jet stream. 

–SUNDAY sees sunny skies and gusty winds return—then a shift in winds to the northeast and east Monday into Tuesday will bring cooler air into the metro area from Lake Michigan.

–But it looks like a SECOND WARM SURGE could see temps sweep toward 70-deg WEDNESDAY before cooling takes over—cooling which could by the following weekend, bring the area it’s chilliest high temps of the season to date—daytime readings which reach no higher than the low 40s. Even with the predicted late week cooling next week—which takes highs down to the 60s Thursday and the 50s Friday, the week is to post a 6-deg ABOVE NORMAL temp departure is current modeling verifies.

–The week which follows sees Chicago in a BELOW NORMAL TEMP REGIME.

HERE’S MY LATEST THURSDAY CHICAGO METRO FORECAST:

TONIGHT: Increasing cloudiness, breezy and warmer. An unseasonably mild 61-degree low is expected—a reading 22-deg above normal.

FRIDAY: Cloudier than not, windy and unseasonably mild. Scattered showers may impact half the area.  High 72—a late Sept level temp 18-deg above normal.

FRIDAY NIGHT: Showers becoming more widespread, quite windy and mild. Isolated thunder possible. Low 57.

SATURDAY: HIGH WINDS THREATEN BY AND DURING THE AFTERNOON. Cloudy and showery with a few possible thunderstorms into morning. Then partial clearing, becoming VERY WINDY and still mild. Wind gusts topping 50 mph are likely. High 67.

SUNDAY: Sunny, windy and unseasonable mild. Gusts 20 to 30 mph likely. High 70.

MONDAY: Increasing cloudiness, breezy and cooler. Winds shift off Lake Michigan. High 56—around 50 lakeshore.

TUESDAY: A good deal of cloudiness and breezy with seasonable temps. Wind blows off Lake Michigan a second day.  High 59—but low to mid 50s lakeshore.

WEDNESDAY: Partly sunny and warmer. High near 70.

THURSDAY: Clouding over, continued mild. High 65.