A windy, messy Thursday and Thursday evening is ahead.

February’s first measurable snow and potentially the largest snow accumulation here in three weeks is in the forecast.

Winds will increase with mixed sleet, snow and possible freezing rain.

A Winter Storm Warning has been issued for Lake and McHenry counties in Illinois for 6 a.m. Thursday until 9 p.m. Four to seven inches of snow are possible.

A Winter Weather Advisory has been issued from 6 a.m. Thursday until 9 p.m. for Cook, DuPage, Will, Grundy, Kane, Kendall, La Salle counties. One to three inches of snow is possible and ice accumulations are possible. Winds gusts as high as 40 mph are possible.

When will the snow arrive?

Precipitation will impact both morning and afternoon rush hours Thursday.

Precipitation developing as a wintry mix – i.e. snow, sleet and freezing rain — in the 5 a.m. to 7 a.m. time frame in Chicago proper.

In Chicago proper, precip will switch to all snow during the afternoon.

The mix with shift to all snow amid strong northeast winds with gusts building to 40 mph making for a very messy day.

What’s more, temps will settle to freezing, so there will be accumulation and travel issues are a threat, especially on untreated and less traveled thoroughfares.

The evening commute period may prove the most challenging given the fact snow should be falling area-wide and temps hovering near freezing.

Precip is to taper off and end Thursday, shifting as lake effect snow for a time into northwest Indiana.

Temps through the afternoon along coupled with a northeast flow off Lake Michigan suggest lake enhancement of snowfall is likely in the afternoon lasting into Thursday evening and night.

How much snow will the Chicago area get?

In Chicago proper: 2- 4 inches are likely in the city and from I-80 corridor north.

Heaviest totals of 4 to 7 inches are likely northern counties bordering the Wisconsin line north into southern Wisconsin.

Accumulations to taper quickly heading south from the I-80 corridor.

Looking ahead to the weekend & next week

The sun is to emerge Friday and shine brightly leading us into a weekend with generous sunshine, gusty southwest winds and warming temps.

Next week, the final full week of February 2023, is looking interesting on modeling as a huge north/south temp spread develops across the Lower 48. Arctic air will dominate the the northern region of the country from the Upper Midwest to the Northern Plains while unseasonably warm weather holds south. This sets us a powerful west to east jet stream within which there are sure to be embedded impulses–each capable of encouraging moist air to sweep north into the cold air in which Chicago is to sit from Tuesday forward. This raises the specter of periods of wintry precipitation and suggests next week will be a period we monitor for potential snow or a wintry mix here or nearby.