Watch how the National Weather Service’s GFS model sends moisture into the central U.S. with the new spring storm. This is the forecast starting 1am CDT Tuesday

THE FOLLOWING SERIES OF PREDICTED WEATHER MAPS shows how the new spring storm is to traverse the country. This panel is the forecast starting 7am CDT Wednesday

FROM JULY-LEVEL WARMTH TO FEBRUARY-LEVEL CHILL

Chicagoans have been on the receiving end of a jarring—and all too APRIL-LIKE 44-degree temperature pullback over the past 2 days. It’s a temp plunge which has effectively taken the area from July-level warmth on Saturday back to a late February-level chill.

• Saturday’s high of 83 is but a distant memory as we move into Monday evening in the wake of an afternoon high of just 39-degrees—a reading 21-degrees below normal. Add to the chill and the 40-mph gusts which delivered the overnight and Monday morning snow that coated the ground near O’Hare with 0.4 inches of snow, just a trace at Midway, and as much as 1.8 inches fell in far north suburban Harvard and in Rockford.
• A FREEZE WARNING HAS BEEN ISSUED FOR TONIGHT INTO EARLY TUESDAY as skies clear overnight and lead into a gorgeous sun-filled Tuesday. The reappearance of the April sun will allow temps to rebound closer to seasonal April levels Tuesday.

GET SET FOR MORE TEMPERATURE GYRATIONS AND A WINDY NEW SPRING STORM LATER THIS WEEK

• April’s richly deserved “FINICKY” characterization will continue to be on display with lowering pressures and the development of a new spring storm in the Plains in the Wednesday/Thursday time frame. This time frame is expected to at first pull chilly ESE winds off the Lake Wednesday, producing lake cooling over the area from Chicago north during the day as southern suburbs surge into the 70s.
• A northbound warm front extending from the Plains storm will sweep north across the Chicago area Wednesday night and place the city in the 70s for a day Thursday. Clusters of showers and thunderstorms are likely to sweep the area as the northward surge of warmer, moister Gulf air makes its move into the area. This sets the stage for potential active t-storms here in the storm’s warm sector. The area has been assessed a MARGINAL RISK of severe weather in the Thursday/Thursday night time frame by the Storm Prediction Center (SPC). That’s a LEVEL 2 on the 5 LEVEL RISK SCALE employed by the Storm Prediction Center.
• Temperatures take a hit Friday in the wake of a Thursday night frontal passage. Then, our interest turns to a possible wave forming on the cold front, which by Friday night and Saturday will be east of us. Should such a wave develop, it will toss cold moisture back into returning chilly air Friday night and Saturday. This raises at least the potential of a round of chilly rain which could mix with wet snow again over at least a portion of the area. There are many details on such a development which are hardly, at this distance in time, carved in stone but will be interesting to monitor.

THE CHICAGO AREA WAS ON THE SOUTH END OF A SIGNIFICANT SPRING SNOWSTORM

This snowstorm generated nearly 2 feet of snow over western Wisconsin’s Thorp—situated 266 miles northwest of Chicago. What’s fascinating is the fact that area had temps in the mid to upper 80s only days ago. In fact, LaCrosse, Wisconsin reported a record-breaking 90-degree high late last week. A fresh cover of snow has occurred over a region in which last week’s unseasonable warmth had raised flood concerns with a rapid snowmelt. How quickly April weather can change!