FIRST, THE WEDNESDAY WEATHER HEADLINES

–A gorgeous and mild late autumn day Wed saw the temp hit 70 in Chicago—-a reading 18-deg ABOVE NORMAL

–November 2022 is off to a warm start—currently running 11.1-deg warmer than a year ago and 10-deg above normal. Today’s average temp was the 13th in a row to average ABOVE NORMAL. And EVERY DAY this month—each of the opening 9 days—has posted a temp surplus.

–It gets even warmer Thursday amid strong SSW winds beneath the east side of an autumn storm producing a BLIZZARD with local one foot of greater accumulations in the northern Plains east into far northern Minnesota.

–BUT BIG WEATHER CHANGES LOOM for Chicago.  Temps crash with a cold frontal passage late Thursday night. The cold air it ushers into the area on strong NW winds Friday through the weekend is to be the COLDEST TO DATE THIS SEASON.  In fact, the string of 30-deg daytime highs forecast Sat & Sun will be the most to occur here in the more than 7 months since last March!

–And the cold pattern is likely to continue—reinforced regularly with new surges of chilly air through next week and into the week which follows.

–Strong ridging aloft over Alaska—in other words, a NORTHWARD BUCKLE in the jet stream, possibly driven in part by winds there off an abnormally “warm” pool of ocean water in the western Gulf of Alaska and North Pacific—will keep upper winds blowing into the Lower 48 from Canada.  This is to set up a HUGE AREA OF BELOW NORMAL TEMPS which are likely to exhibit STAYING POWER next week and beyond almost from coast to coast.

–The incoming cold air will be quite unstable by this weekend. In other words, temps will drop within the incoming air mass quickly with height, encouraging air to rise and fostering a good deal of Saturday cloudiness. With temps just a mile above the surface forecast in the mid-teens, clouds will be able to produce snow flurries which may fall to the surface in Saturday’s gusty winds.

–Across Lake Michigan, in sections of northwest Indiana and western Michigan, the cold weekend air is to produce lake effect rain and snow showers Saturday—a lake effect set-up which breaks down slowly Sunday.

–This weekend is likely to average a jarring 23-deg colder than last.

–79% of Novembers have ended up producing some sticking snow. We don’t see the system likely to do that just yet—but it may be out there. Seven of 10 recent runs of the NWS GFS ensemble and deterministic models plus 7 of the 10 most recent runs of the latest European Centre’s ensemble model indicate that Saturday’s flurries may not be the last over the coming two weeks. And 9 of the most recent runs of the Canadian global forecast model put at least flurries into Chicago again over the coming 2 weeks.

HERE’S MY LATEST WEDNESDAY CHICAGO METRO FORECAST:

TONIGHT: Partly cloudy, breezy and milder. Low 59—which is more than 20-degree ABOVE NORMAL.

THURSDAY: Partly sunny, turning windy and unseasonably warm. A near record or record setting high is likely. High 74—23-degress ABOVE NORMAL.

THURSDAY NIGHT: Partly cloudy, windy and turning colder late. A few sprinkles or isolated showers possible toward morning—but with low coverage. Low 40.

FRIDAY: Opens cloudy with a sprinkle or shower possible in spots. Then partly cloudy, windy and markedly cooler. High 45—but falling to the upper 30s by nightfall.

SATURDAY: THE WEEKEND WILL SEE THE CHILLIEST WEATHER TO DATE THIS FALL. A good deal of cloudiness, windy and colder. Peeks of passing sun possible—but so too are passing flurries in Chicago and west. More substantial lake effect rain and snow showers are likely to develop downwind of Lake Michigan in portions of northwest Indiana and western Michigan. High Saturday 37—a reading 13-deg BELOW NORMAL.

SUNDAY: Sunshine gives way to clouds, not nearly as windy—but continued chilly. High 39.

MONDAY: More clouds than sun, chilly. High 41.

TUESDAY: Cloudy and chilly. Chance of some rain possibly mixed with some ice pellets or wet snowflakes. High 41.

WEDNESDAY: Mostly cloudy and chilly. Chance of some passing flurries. High 37.