Lake snow squalls intensifying
11PM Update: A band of heavy lake effect snow will slowly drift south over the Chicagoland area tonight.
The dominate or main lake snow plume is talking shape with heavy snow over eastern Lake County. At this hour, roads in eastern Lake County-IL are 100% snow covered and road crews can’t keep up with 1-3″ per/hour snow rates.
Be prepared for rapidly changing road conditions (wet to 100% snow) all night, which is a characteristic of lake snow.
At approximately 10PM, lake snow contributed to a 48 car pileup on the inbound Kennedy expressway near North Ave.
5PM Update: Here’s the latest on the “lake snow phase” of this storm.
Lake snow showers are expected to develop around 7-8PM this evening. Wind convergence will consolidate the snow showers into a relatively narrow plume of heavy snow squalls by 10-11PM. Within this plume, very heavy snow is likely with snowfall rates of 1″-3″ per hour.
This plume of snow is expected to be a persistent feature throughout the night, although it won’t be sitting over the same location. A Lake Effect Snow Warning is up for Lake (IL), Cook & DuPage Counties from 7PM tonight until 4PM Tuesday. Some locations may only see a couple hours snow during that period due to the progressive nature of these snow plumes.
New snowfall totals (on top of what’s already on the ground) within the warning area will range from 3″ to 10″. A few spots could exceed that 10″ mark.
Many southern suburbs will get in on the snow too. A Lake Snow Advisory has been posted for Will and Lake (IN) counties.
We should make it through tonight’s evening rush without major issues. Tomorrow, heavy snow may be ongoing during the morning rush from downtown Chicago southward along and east of the I-57 corridor (see graphic below).