Chicago weather: Near-impossible travel possible with double-digit snow totals in heaviest areas

Chicago weather: Winter storm heading to Indiana, Chicago area

FOX 32 News at 9 brings you the latest breaking stories from across the Chicagoland area.

CHICAGO - Get ready for Chicagoland’s first real dose of Winter tonight and Monday.

The lake effect snow machine has flipped to ‘ON’ with the cold air mass that has invaded the Great Lakes Region. With air temperatures falling into the 20s tonight and Lake Michigan water temperatures still in the 50s, this is a perfect recipe for heavy lake effect snow. Let’s break down the details.

RELATED: Chicago area schools announce closures, shifts to E-learning ahead of snowstorm

What we know:

A WINTER STORM WARNING has been issued for the following counties:

• Lake (Ill.): 9 p.m. Sunday to 6 a.m. Monday
• Cook: 9 p.m. Sunday to noon Monday
• Eastern Will: 9 p.m. Sunday to noon Monday
• Kankakee: Midnight to noon Monday
• Lake and Porter (Ind.): 9 p.m. Sunday to 6 p.m. Monday
• LaPorte: Now to midnight Tuesday

A WINTER WEATHER ADVISORY has been issued for the following counties:

• DuPage: 9 p.m. Sunday to noon Monday
• North and South Will: 9 p.m. Sunday to noon Monday
• Newton: Midnight to 6 p.m. Monday
• Jasper: Midnight to 6 p.m. Monday

Areas in the Winter Storm Warning will be the hardest hit with the heaviest snow totals expected. The closer in proximity that you are to Lake Michigan, the higher your potential snow totals will be.

Two waves of lake effect snow coming to Chicagoland

The first wave arrives late this evening, after 9 PM or so. A band of moderate to locally heavy snow will surge inland, weakening as it gets farther inland from the lake.

The second wave comes as a narrow band of lake effect in the early morning hours, likely forming around 3-4 AM. It will first move ashore in NE Illinois and then make its way around the lake into NW Indiana during the mid/late morning into the afternoon. This narrow band will only be maybe 10-15 miles wide, so not everywhere will be seeing snow all morning tomorrow. However, this band will have the potential to drop 2-3" per hour, so expect quickly changing driving conditions when the lake effect moves over your area on Monday!

How much snow are we talking?

Unfortunately, this isn’t a very straightforward forecast. Lake effect snow is often times very localized. Snow totals will vary greatly from one location to the next. Will all locations within the Winter Storm Warning see massive snow totals? No. But for those of us IN the Warning, we need to be prepared. The key here is to talk about potential snowfall...and locations within the Warning appear to have the potential for 6-10+" of snow.

The amount of snow that piles up will largely depend on how quickly this narrow band of lake effect moves though any given location. With snow rates expected to be as high as 2-3" per hour at times, if the band becomes somewhat stationary for a few hours over any given location, then that location will easily end up in the 6-10+" range. Again, does that mean all the counties in the Warning will be blanketed in 6-10" of snow? No. That isn’t how this event is going to unfold.

It appears the most likely scenario for 6+ inches of snow will be in eastern Lake (IL), eastern Cook, eastern Will, Lake (IN), Porter, LaPorte, and possibly Kankakee. So those of you in these areas should prepare for quickly changing road conditions and periods of heavy snow/whiteout conditions.

Areas in the Winter Weather Advisory (DuPage, northern and southern Will, Newton and Jasper) will still see snow, but impacts shouldn’t be quite as intense. Totals within the Advisory area will likely end up in the 2-5" range.

Why is this a big deal?

With the intense snow rates in combination with northerly winds gusting over 30 mph, whiteout conditions are expected at times late tonight into Monday.

Drivers should be aware of quickly changing road conditions, especially if traveling near the lake in NW Indiana or NE Illinois. During the heaviest of snow bands, snow rates will be high enough that plows will not be able to keep up. Expect significant impacts to your commute if caught in lake effect snow.