In terms of the summer-level warmth which produced the 2nd greatest number of 80 degree and warmer days of any year since records began here 153 years ago in 1871, its unceremonious departure hit like a wall.

Monday’s post snow 39 degree high was 44-degrees off the 83 degree which sent many to area beachers—and others outdoors to enjoy the warmth.

A 2 day drop in temps is hardly a record here. Chicagoans experienced a 61 degree drop—from 74 to 13 degree Nov. 11-12, 1911—which holds at the city’s greatest 2 day temp plunge.

But the drop was the equivalent of moving from July level readings back to Feb level temps in a 48 hour period.

A Freeze Warning has been issued from midnight tonight to 8 a.m. CDT Tuesday morning by the National Weather Service Chicago. Temps are likely to drop into the low 30s in the city and to the mid to upper 20s inland as skies clear overnight.

Beyond that in the coming week—get set for a continuing ride on the April thermal roller coaster.. Temps will rebound to 60—which is close to normal Tuesday.

But strengthening east/southeast winds off Lake Michigan will set up a huge north/south temp spread Wednesday as a warm front makes its way north across half the metro area. Temps from Chicago north will blow off the chilly 44-deg lake waters—so highs on the lakeshore from Chicago north will make it only to 50—spending much of the day in the 40s. Away from the lake, temps will warm to the upper 60s well inland by the south suburbs Wednesday will see low 70s—and low to mid 70s will be common across the area Thursday,

The warmth precedes a spring storm whose warm sector will include an influx of Gulf moisture, raising prospects of some active t-storms as a cold front passes Thursday night.

At that time, a marginal severe weather risk is being indicated by the Storm Prediction Center.

Cooler weather follows Friday—and the potential of a second wave developing on the cold front to Chicago’s east comes into play. Such a development would sweep moisture back into the cooler air and raise prospects for a chilly rain in Friday night/Saturday time frame. There are even indications temps may be chilly enough to support mixed wet snow in some areas close-by. Many details have yet, at this distance in time, to be worked out—but this is a scenario we’ll be following closely.



MONDAY NIGHT: Clearing, breezy and colder. Lows 34 in the city—but upper 20s colder inland locations.

TUESDAY: Sunny and milder. High 58—but cooler lake breezes develop later in the day.

TUESDAY NIGHT: Increasing cloudiness. Chance of scat showers—possible a few isolated thunderstorms— toward morning. Low 43.

WEDNESDAY: A good deal of cloudiness, warmer—especially southern sections. Chance of several showers or t-storms impacting 30% of the area. Highs ranging widely from near 50 on the lakeshore from Chicago north—to 68 well inland—and the low 70s south suburbs.

THURSDAY: Warmer and windy. Cloudy spells. Scattered showers grow more numerous and thundery with up to 80% of the area likely to see rain before day’s end. High 73.

FRIDAY: Clouds break for some mixed sun at times. Cooler. High 65—but cooler as winds shift northeast off Lake Michigan in the afternoon.

FRIDAY NIGHT AND SATURDAY: Cloudy, breezy and colder. Chilly rain possible—could be mixed with some wet snow in parts of the area. Low Friday night 38. High Saturday 44.

SUNDAY: Partly cloudy, chilly for the season. High 46.

MONDAY: Cloudy spells and cool. Spotty showers possible. high 54.