WHAT A DIFFERENCE A DAY MAKES! The area enjoyed 100% of its possible sun Tuesday—a development which boosted temps 15 to 20 degree above levels observed Monday. The day’s high, likely to approach 58 degree after a chilly 32 degree low Tuesday morning will nearly reach the “normal” high of 60 Wednesday.

A new spring storm is centered over Colorado and Wyoming and is set to impact Chicago’s weather in a number of way in the next several days. Temps within its southern flank have hit 90 Tuesday afternoon in western Kansas with 80s nearby.  It’s this warm air which is to be ushered northward behind a northbound warm front in the next 24 hour. That warm front will reach Chicago’s southern suburbs with 70 to near 80 degree temps—-even as a brisk east/southeast flow off Lake Michigan imports a chill over the city and North Shore much of the day Wednesday.  

Scattered t-storms are to develop along and north of the warm frontal boundary Wednesday—impacting 30% of the Chicago area Wed afternoon and 50% of the area as the warm front swings across the city Wed night.  

While late day temps will have reached the 70s to near 80 over area south of Chicago, temps may hold to the upper 40s to mid 50s in the city and areas north much of the day Wednesday—then rise into the 60s Wed night.

Thursday sees the Chicago area back in the 70s but also in a warm, unstable air mass into which Gulf moisture has moved. The buoyant moist air ascending into jet stream winds aloft threatens some clusters of active t-storms—Thursday.  The area is being assessed a LEVEL 2 SEVERE WEATHER RISK on the Storm Prediction Center’s 5-LEVEL SCALE FROM WED NIGHT INTO THURSDAY NIGHT.

Friday sees precipitation pause and temps cool modestly into the 60s. But the potential for a secondary wave to develop over the southern Ohio Valley and sweep northward as Chicago becomes immersed in a much chillier northerly wind flow Friday night and Saturday could be the harbingers of some chilly rains and temps will slide back into the mid 40s to low 50s for the weekend.

And a cooler than normal weather pattern appears likely to dominate through next week and the weekend which follows.

This week’s temps are to average 17 degree cooler than last week’s (with its string of 80 degree highs) coming in close to 3 degree below normal. Next week’s temps may slip to levels 6 degree below normal.


TONIGHT: Partly cloudy and cool. Low 40.

WEDNESDAY: More clouds than today and breezy. Several clusters of showers and t-storm may develop. A huge north/south temp variation is to develop with a day time high of 57 at O’Hare but in upper 40s to low 50s along Lake Michigan from Chicago north. South suburbs will warm to the 70s—even close to 80 by late in the day.

WEDNESDAY NIGHT AND THURSDAY: Much warmer and becoming fairly windy. Cloudy spells with some clusters of showers and thunderstorms impacting 50% of the area at times Wed night and as much as 80% of the area Thursday—most numerous in the afternoon and evening. Some heavy storms possible. Temps rise into the 60s Wed night. High Thursday 74.

FRIDAY: Partly cloudy, windy and cooler. High 63.

SATURDAY: Cloudy, blustery and much cooler. Period so chilly rain likely. High 50.

SUNDAY and MONDAY: Partly cloudy and cool. High Sunday 49, Monday’s high 55.

TUESDAY: Cloudy, breezy and cool. Chance of rain. High 59—but 40s along Lake Michigan.