Illinois Blizzard: Thundersnow, 50 MPH Winds, Snow Totals

CHICAGO, IL — Parts of Illinois were reporting rain, sleet, snow and even thundersnow with much of the Chicago area under a blizzard warning. Cook, DeKalb, DuPage, Grundy, Kane, Kendall, Lake, LaSalle, McHenry and Will counties are all under a blizzard warning until 9 a.m. Monday. According to the National Weather Service, the updated time frame for the worst conditions is 8 p.m. Sunday to 4 a.m. Monday.

Thundersnow was reported in Amboy in Lee County, and near-whiteout conditions were reported in other parts of Illinois, according to WGN. Illinois Storm Chasers also said thundersnow is possible in other areas during the height of the storm as snowfall rates reach one to three inches per hour across portions of. north and central Illinois.

Heavy snow is expected with total snow accumulations of seven to 11 inches, with localized amounts up to 13 inches of snow. The NWS said there will be lower amounts across southeast Cook County and downtown Chicago.

The National Weather Service reported "quickly deteriorating conditions" across much of Illinois and advised residents to postpone trips unless there is an emergency.

Wet snow will fall across much of northern Illinois late Sunday and Sunday night. The NWS said snowfall amounts will also decrease to the southeast, with amounts of one to three inches expected southeast of the I-55 corridor in eastern Illinois and northwest Indiana. This storm will also be accompanied by strong winds gusting to 45 mph. The winds will produce blowing and drifting snow and poor visibility.

More than 500 flights were also canceled at Chicago airports due to the winter storm.

O'Hare, Midway Cancel Over 500 Flights With Snowstorm On The Way

Forecasted snowfall totals

According to the NWS, predicted snowfall amounts for parts of Illinois were as follows as of Sunday evening:

• Dekalb: 8-12 inches
• Rockford: 8-12 inches
• Elgin: 8-12 inches
• Waukegan: 8-12 inches
• Joliet: 6-8 inches
• Chicago: 4-6 inches
• Kankakee: 2-3 inches

Snowfall so far

These are the latest snowfall reports for Illinois: as of just after 12 a.m. Monday:

• Rockford Airport: 11.7 inches
• DeKalb: 8.3 inches
• Saint Charles: 5.5 inches
• Batavia: 5.1 inches
• Schaumburg: 4.5 inches
• Lombard: 4 inches
• O'Hare Airport: 3.3 inches
• Romeoville: 1.4 inches
• Midway Airport: 1.4 inches

Travel could be very difficult, according to the NWS. Snow-covered roads and significantly reduced visibility are expected. Snowfall rates in excess of two inches per hour are also possible.

This snow is expected to be very heavy and will be difficult to shovel. The strong winds and heavy snow could also cause falling tree limbs and possible power outages. If you must travel, keep an extra flashlight, food and water in your car. The latest road conditions for the state you are calling from can be obtained by calling 511.

Hourly forecast

Here's a look at your hour-by-hour forecast for Sunday and early Monday:

• 8 p.m. - Rain and snow, 34 degrees, wind northeast at 26 mph.
• 9 p.m. - Snow, 33 degrees, wind north northeast at 26 mph.
• 10 p.m. - Snow, 33 degrees, wind north northeast at 28 mph.
• 11 p.m. - Snow, 33 degrees, wind north northeast at 28 mph.
• 12 a.m. - Snow, 32 degrees, wind north northeast at 28 mph
• 1 a.m. - Snow, 32 degrees, wind north at 28 mph.
• 2 a.m. - Snow, 32 degrees, wind north at 28 mph.
• 3 a.m. - Snow, 31 degrees, wind north at 28 mph.
• 4 a.m. - Snow, 31 degrees, wind north at 25 mph.
• 5 a.m. - Likely snow, 31 degrees, wind north at 24 mph.
• 6 a.m. - Chance of snow, 31 degrees, wind north northwest at 22 mph.

Photo by Kathleen Culliton/Patch Staff