We are now just a day away from this potential winter storm, and still plenty of uncertainties exist regarding the amount of accumulating snow that we see here in Champaign-Urbana. When does the rain actually change over to snow? What if the storm shifts just 25-50 miles to the east at the last moment and we end up outside the heaviest snow band? What if dry air works its way into the system cutting off the heavy snow sooner than forecast?
With all of that being said, there is still the potential for significant accumulating snow in Champaign-Urbana and surrounding areas. Right now, a blend of all potential factors leads me to believe that rain changes over to snow between 10 AM and 2 PM, with a steady heavy and wet snow falling through the afternoon and evening. Gusty winds over 40 mph could create white out conditions, especially in rural areas. This will be true even if we don't see high amount of 4-6". In a "best case scenarion" where rain changes over to snow during the morning hours and falls through the day without being interupted during the afternoon, and C-U does end up in the heaviest band of snow - then amounts of 4-6"+ will be possible. But any of these factors working in... a late changeover from rain to snow, dry air ending the snow earlier in the day, a shift in the track of the heaviest snow band... could also dramatically reduce the snow totals we see here in CU, which is why I am going with a conservative, broad range of 2-6" total.