Frigid arctic air is on the move—and it sweeps into Chicago overnight sending temps and wind chills plunging. By morning, Chicago’s temps will have fallen to 0 in the city and wind chills are to dive into the 10 to 20 below range. Wind gusts are to build to 30 mph at time overnight—a bitterly cold weather set-up—one which renders the chill dangerous.

A wind chill advisory kicks in at 11pm tonight and runs through 10 am Friday.

What’s happening late Thursday in Minnesota and the Dakotas is a preview of what’s coming. Temps have dropped sub-zero and wind chills are down to 35-below in northwest MN and parts of North Dakota.

Temps and wind chills drop to 14/0 at 9pm; 7/-10 at midnight and to -1/-17 in the city by daybreak—and Friday’s high will rise to 12—a drop of 21-deg from Thursday’s 33 -deg high.

Chicagoans basked in 100% of the city’s possible sun for a second day—a treat after a record cloudy January.

Sub-freezing temps will cover 80% of the Lower 48 by morning—but will by Sunday afternoon shrink to just 10% of the country.

Full forecast details at the WGN Weather Center

The incoming cold blast will be brief—and will yield to an extended period of late winter above normal temps. This week is to come in 8-deg below normal—but the HUGE PATTERN CHANGE means next week’s temps will average an eyecatching 20-deg warmer and more than 10-deg above normal—with many 40-deg daytime highs.

In fact, current modeling had each of the coming 15 days AFTER FRIDAY surging 8 to 15-deg above normal.

Latest Metro Forecast

WIND CHILL ADVISORY from 11pm tonight through 10 am Friday morning

TONIGHT: Windy and turning sharply colder. Scattered clouds with wind gusts building to 30 mph at time producing a dangerous level of chill. More clouds and a few flurries possible downwind of Lake Michigan in northwest Indiana.Temps plunge to 4 above to 2-below in the city by morning and to 4 to 8-below coldest northwest suburban locations. Wind chills by daybreak drop to 10-below to 20-below.

FRIDAY: Mostly sunny but quite cold. Gusty morning winds ease in the afternoon—but Friday highs only reach 12-deg.

FRIDAY NIGHT: Partly cloudy and cold—but with steady or rising temps late. Low 10 in the city; single digits northwest—but rising into the teens by morning.

SATURDAY: Clouds move in, becoming windy and noticeably milder. High 21-deg warmer than Friday—reaching 37 Saturday afternoon.

SUNDAY: Partly sunny, windy and milder. High 41.

MONDAY: Becoming cloudy, breezy and quite mild for the season. High 48.

MONDAY NIGHT: Chance of rain showers Monday night.

TUESDAY: More cloudy than not, still mild but less windy. High 49.

WEDNESDAY and THURSDAY: Growing prospects for rain. Temps remain above normal. High Wednesday 41..lower lakeshore. Thursday’s high 43.