Healthy rains are to reach the Chicago area Wednesday night toward midnight and continue into Thursday. The heaviest will be in the city, based on current modeling, in roughly the 5 a.m. to the 8 a.m. or 9 a.m. Thursday time frame. This would coincide with a good part of Thursday’s morning commute period if that thinking verifies.

It’s during that period upward vertical motion through the atmosphere generated a powerful pocket of jet stream winds, is to be situated over the area—a period most apt to support at least some embedded thundery downpours. Rising air, particularly rising air with the kind of moisture predicted to be in the air Thursday morning, cools most efficiently and therefore is more likely to produce rains and even some lightning and thunder.

Snow possible in parts

For areas northwest of Chicago Thursday afternoon — toward Rockford and Belvidere and essentially the area from McHenry, Boone and Winnebago counties — the storm’s precipitation may end as a period of wet snow. And some snowflakes may even enter the scene Thursday afternoon and evening toward the Fox Valley, some occurring briefly brushing areas as far east as Chicago though that’s not a 100% certainty.

How much rain will we get?

When all is said and done, it appears much of the Greater Chicago area could be in for 0.60″ to as much as 1.60″ of rain which would make the incoming storm system the heaviest precipitation-producer here since the 1.12″ which fell more than a month ago on January 3rd.

Strong winds likely too

For a time Thursday afternoon and evening, the storm’s powerful backside winds could include 40 to 50 mph wind gusts.

What will it be like this weekend?

A quiet weekend lies ahead. And the modestly chillier temps which take up residence here later this week give way to milder than normal weekend temps with the 40s returning.

More rain and snow next week

Next week looks active with two potential precip systems showing up on models. The first is likely to bring rain Tue/Wed if current forecast trends continue. A change to colder weather later in the week makes the form a second late week storm system’s precip takes here possibly more problematic. We in Chicago will be closer to its rain/snow line. It will be interesting to follow developments with that system.

Putting February 2023’s lack of snow and precip to date– and the upcoming storm’s potential rain tallies into perspective

My WGN meteorological colleague Mark Carroll notes that February, 2023’s opening 7 days have produced now snow and just a trace of precipitation. Mark notes it’s the first time in 32 years (since 1991) so little precip has fallen in the month’s opening week. It’s been 18 years since a February’s opening days have gone without snow in the city.