No surprise why it dumped snow in portions of east-central Illinois when consulting a NAM-3km forecast sounding from last night. High amounts of negative omega in the dendritic growth zone and semi-descent lapse rates led to 1-2” per hour snowfall rates in spots. #cILwx pic.twitter.com/eKSs1Rz7TF

— Thomas Kauzlarich (@Wx_Geek) January 3, 2021