A low pressure system is located over southeastern Minnesota. This, combined with a strong upper level jet, is producing strong lift, which is combining with moisture from the Gulf of Mexico to produce intense snowfall across central Illinois. Several locations in the area have already received in excess of 3 inches of snow at the time of this writing. As the low pressure system tracks across central Illinois on Tuesday, heavy snowfall is expected to occur with storm total snowfall of 6-9 inches expected before the system finally moves off to our east. As the storm departs, a tight pressure gradient is expected, resulting in strong winds producing blowing snow and near-blizzard conditons on Tuesday night. Furthermore, these strong northwest winds will bring cold Canadian air into central Illinois, resulting in colder temperatures on Wednesday and Thursday. On Friday a weak upper level system will move over the area, bringing clouds to the area, as well as warmer temperatures. An Alberta clipper system is expected to move across the area on Saturday night, bringing the chance for snow, however any accumulations should be minor.
Forecast in detail…
Winter weather advisory from the National Weather Service in effect until 6 AM Wednesday.
Tonight: Cloudy with snow, heavy at times. Low of 15 with winds out of the east at 5-10 MPH. New snow accumulation of 3-5 inches expected.
Tuesday: Cloudy with a 60% chance of snow. High of 26 with winds out of the west-northwest at 10-15 MPH, increasing to 15-20 MPH late in the afternoon, with gusts to 30 MPH. New snow accumulation of 1-3 inches expected.
Tuesday Night: Cloudy with a 40% chance of snow and near-blizzard conditions possible. Low of 18 with winds out of the west-northwest at 20-25 MPH with gusts to 35 MPH. New snow accumulation of up to 1 inch expected.
Wednesday: Partly cloudy. High of 27 with winds out of the west-northwest at 15-20 MPH, diminishing to 10-15 MPH in the afternoon.
Wednesday Night: Fair. Low of 11 with winds out of the northwest at 5-10 MPH.
Thursday: Sunny. High of 27 with winds out of the northwest at 5-10 MPH.
Thursday Night: Partly cloudy. Low of 9 with winds out of the east-northeast at 5-10 MPH.
Friday: Mostly cloudy. High of 31 with winds variable at 5-10 MPH.
Friday Night: Mostly cloudy. Low of 16 with winds out of the north-northwest at 5-10 MPH.
Saturday: Mostly cloudy. High of 35 with winds out of the west at 5-10 MPH.
Saturday Night: Partly cloudy with a 20% chance of snow. Low of 21 with winds out of the west at 5-10 MPH. New snow accumulation of up to 1 inch expected.
Sunday: Partly cloudy. High of 29 with winds out of the southwest at 10-15 MPH.
Sunday Night: Partly cloudy. Low of 12 with winds out of the west-southwest at 5-10 MPH.
Monday: Partly cloudy. High of 28 with winds out of the west at 10-15 MPH.