LINCOLN — Yes, that was thunder you heard and maybe even lightning you saw during this morning's snowfall, National Weather Service meteorologists said.
There were even two cloud-to-ground lightning strikes in Champaign County this morning, said meteorologist Kirk Huettl at the weather service office in Lincoln.
"Even in the wintertime we can get these types of systems that can be convective in nature," said Huettl. "Generally this whole line filled in between Alton and Champaign with the lightning strikes concentrated around Champaign and north of St. Louis.
"I think every winter we have one or two thunderstorm events with winter precipitation. It's not like it never happens."
Worst winter ever? Ask Tom Kacich what he thinks here
The lightning strikes did not cause any damage, he said.
"A lot of times lightning hits the ground and doesn't damage things too much. But there is a chance for that in the summertime when people are out more, playing baseball or whatever. That's when it is more common for lighting strikes to actually hurt people."
The "thundersnow" was especially prevalent in the Champaign area, said meteorologist James Auten.
"There are some areas of this storm that are really enhanced. The Champaign area, toward the northwest is starting to see thunder occurring with the snow," said Auten. "What that does is it creates heavier snowfall and it can also change it over to sleet and what we call graupel, which is like a small hail. In other words it makes it worse.
"It's unusual. It doesn't happen a lot. Conditions have to be just right. What's going on is that inside this area of precipitation, which is an area of freezing rain and sleet and snow, you're getting convective elements so that there are thunderstorms embedded in it. With the thunder it just increases the precipitation that is falling.
"It would be similar to rain showers moving over an area in the summer. When there's a thunderstorm with it you get heavier rain. It has the same effect. It just increases the rate at which the stuff is falling. You get more snow, more sleet, more freezing rain even. That just makes it that much worse."
Auten said he's still hopeful that the snow and freezing rain will change over to rain in the Champaign area later today.
Forecasters are still calling for 3 to 5 inches of snow today, but warming conditions Tuesday through Friday. Thursday's high should be near 50 degrees, the weather service said.
Tom Kacich/The News-Gazette
All flights in and out of Willard Airport have been canceled, except two incoming flights tonight, one from Dallas and one from Chicago.
Latest on National Weather Service advisories:
Most of East Central Illinois is under a winter weather advisory until 6 p.m. Monday. However, a winter storm warning is in effect for McLean and Ford counties until 6 p.m. Monday and until 9 p.m. Monday for Iroquois County.
Freezing rain, sleet and snow are expected across our area, with two to five inches of snow and sleet across the Champaign-Urbana area. Four to eight inches are possible as you go north into Ford and Iroquois counties.
Freezing rain and sleet are already causing problems for drivers, especially west and south of Champaign-Urbana. Also, blowing snow is drifting onto roads. Several cars were involved in an accident on Monday morning on Interstate 72 at Route 47.
The state police district that includes Ford and Iroquois counties has issued a travel advisory.
"The Illinois State Police are advising motorist to be cautious while traveling today. Hazardous travel conditions with drifting snow and ice is expected. Interstate 57 is currently experiencing light to moderate snow with patches of snow and ice throughout Kankakee, Iroquois and Ford Counties. Secondary roads are also snow covered and icy.
"Motorists are advised to be cautious while driving near and around snow plows. Motorist should also be cautious, slow down, and move over for emergency vehicles assisting motorists on the roadways.
"The Illinois State Police are asking drivers to monitor changing weather conditions, limit their travels, and be prepared to allow plenty of time to reach your destination. Drivers are also encouraged to put extra water, food, and warm clothing their vehicle. Please contact your nearest police department if you vehicle becomes disabled or involved in a crash.
"If you decide to drive please slow down and buckle up."
Here is the National Weather Service's Central Illinois site, with forecasts and advisories.
Here is the state transportation department's winter road conditions site.
National Weather Service has issued a winter weather advisory for snow and sleet for nine area counties from 6 a.m. to 6 p.m. Monday.
Affected areas include Champaign, Coles, Dewitt, Douglas, Edgar, McLean, Moultrie, Piatt and Vermilion counties.
A winter weather advisory for snow and sleet is in effect from 9 a.m. to 6 p.m. Monday in Ford and Iroquois counties.
According to the weather service, snow and sleet will begin moving into areas west of Peoria by sunrise and spread east to the Indiana border through late morning.
Precipitation is expected to continue into the afternoon hours, diminishing near the Indiana border toward sunset.
Snow accumulations of 2 to 3 inches are likely along and north of Interstate 74.
South of Interstate 74, snow accumulations of 1 to 2 inches are expected.
Southeast winds of 10 to 20 mph are forecast to gust to around 25 mph during the morning and then diminish as winds shift to the southwest.
Snow is expected to cause significantly reduced visibilities in the heavier snow bands, and roads will rapidly become snow-covered and slippery.