Wednesday saw the Chicago area’s heaviest snowfall of the lackluster 2022-2023 snow season.

The 3.5 inches preliminary O’Hare snow total makes this not only this season’s heaviest officials city snowfall to date, it’s the Chicago O’Hare’s heaviest snow tally since 5.2″ fell last Feb 2, 2022, just under a year ago.

It’s also more snow than has fallen here in the past 39 days combined.

Here’s a list of the snow accumulations of 1.5″ or more which have been reported with Wednesday’s snow system. The heaviest thus far running in the 3 to 4.5″ range.

Mark Carroll, my WGN meteorological colleagues, produces this list from COCRAHS volunteer observer reports through 6am CST Wed morning. Note these were tallies through 6am CST. It’s been snowing since then, though snowfall rates have dropped off markedly and temps are hovering at or just above freezing slowing if not completely forestalling additional accumulations:

  • Naperville 3.6 SE 4.5
  • Lombard 1.2 E 4.1
  • Oswego 1.7 WSW 3.6
  • Carol Stream 0.3 SSE 3.5
  • Aurora 3.8 SE 3.5
  • Elmhurst 0.8 ESE 3.5
  • Wheaton 0.8 WNW 3.4
  • Plainfield 4.8 SW 3.4
  • Plainfield 3.9 SSW 3.4
  • Plainfield 2.4 SSE 3.3
  • Joliet 0.7 WNW 3.3
  • Aurora 2.8 WSW 3.2
  • Naperville 4.0 SSW 3.2
  • Park Ridge 0.7 WNW 3.1
  • Geneva 1.0 SSW 3.1
  • Franklin Park 0.5 SSE 3.0
  • Aurora 3.6 SE 3.0
  • Wheaton 2.0 NNE 3.0
  • Villa Park 0.8 ESE 3.0
  • Carbon Hill 3.1 N 3.0
  • St. Charles 0.1 E 3.0
  • Aurora 3.2 WNW 3.0
  • Oswego 1.1 ESE 3.0
  • New Lenox 1.8 SE 3.0
  • New Lenox 2.0 ESE 3.0
  • Morris 1.5 SW 2.9
  • Geneva 0.9 E 2.9
  • Batavia 0.8 W 2.9
  • New Lenox 3.3 E 2.9
  • Palos Park 1.3 SW 2.8
  • Oak Lawn 0.5 SSW 2.8
  • Burr Ridge 1.9 SW 2.8
  • Morris 6.4 ESE 2.8
  • North Aurora 1.5 NE 2.8
  • Homer Glen 0.7 NNE 2.8
  • Winfield 0.8 ENE 2.7
  • Manhattan 4.7 ENE 2.7
  • Mokena 1.3 W 2.6
  • Elk Grove Village 0.6 ESE 2.5
  • Homewood 0.1 ESE 2.5
  • Hoffman Estates 4.6 W 2.5
  • Chicago Ridge 0.2 WSW 2.5
  • Oak Lawn 1.6 WNW 2.5
  • West Chicago 3.5 SE 2.5
  • Geneva 1.3 SSW 2.5
  • Aurora 3.1 WSW 2.5
  • Wilmington 2.6 SE 2.5
  • Bult Field-Monee 4.9 SE 2.5
  • Harwood Heights 0.4 NNE 2.4
  • Oak Forest 0.6 N 2.4
  • Mount Prospect 0.2 NNE 2.4
  • Kankakee 1.4 WSW 2.4
  • Montgomery 0.8 SSE 2.4
  • Bridgeview 1.3 NNW 2.3
  • Oak Park 1.3 NNE 2.3
  • Elk Grove Village 2.2 WSW 2.3
  • La Grange Park 0.7 SSW 2.3
  • Batavia 1.5 WNW 2.3
  • Geneva 1.3 NW 2.3
  • Geneva 0.6 SSE 2.3
  • Bannockburn 0.5 ESE 2.3
  • Peotone 0.4 ENE 2.3
  • Mazon 2.4 SE 2.2
  • Schaumburg 2.0 E 2.1
  • Chicago 5.5 ESE 2.0
  • Evanston 0.8 ESE 2.0
  • Schaumburg 2.9 WSW 2.0
  • Batavia 3.4 WSW 2.0
  • Mundelein 0.5 NNE 2.0
  • Bull Valley 2.5 WNW 2.0
  • McHenry 2.4 E 2.0
  • Crete 2.6 E 2.0
  • Crete 3.3 ENE Franktuary Farm 2.0
  • Mahomet 1.7 NNE 1.9
  • Hoffman Estates 1.6 SE 1.9
  • De Kalb 0.7 SW 1.8
  • St. Charles 6.0 NW 1.8
  • Maple Park 3.9 S 1.8
  • Riverwoods 0.4 ENE 1.8
  • Lincolnwood 1.8 E 1.7
  • Palatine 1.3 E 1.7
  • Rogers Park 1.5 SW 1.7
  • Palatine 1.4 NNE 1.7
  • Elgin 2.5 W 1.7
  • Sleepy Hollow 0.7 W 1.7
  • Buffalo Grove 1.5 N 1.6
  • Mundelein 1.6 WNW 1.6
  • Marengo 0.7 NNW 1.6
  • Long Lake 0.4 S 1.5
  • Woodstock 3.8 SW 1.5

My WGN meteorological colleague Paul Merzlock reports nearly 4″ down on Joliet’s west side as Wednesday morning dawned. A number of other locations are at 3″ and counting as the snow continues to fall.

I’ve included only some of the heavier reports. For a complete list of COCORAHS observer reports, here’s a link.

Visibilities also an issue Wednesday

Visibility is a great proxy for snowfall intensity. When visibilities drop to fractions of a mile, the snow’s coming down quite heavily. In fact, visibility is a parameter used by meteorologists to identify “light” versus “moderate” and “heavy” snow intensity.

Here are maps of visibilities at 9am CST Wednesday morning.

Here are the snow intensities used to delineate between “light”, “moderate” and ” heavy” snow intensity: “The standard relationship between snowfall intensity and visibility used by many national weather services (1/4 mile or less visibility corresponds to heavy snowfall intensity, between 5/16 and 5/8 mile corresponds to moderate intensity, and greater than 5/8 mile corresponds to light intensity)”