Soak up the sunshine and mild temperatures we have today, because big changes are on the way. Through the day on Tuesday, much colder air will sink into the Heartland from the northwest. Precipitation will also move in with this cold air. As we move through the afternoon and evening hours, some snow could mix in with the rain. This could bring some accumulating snowfall on elevated surfaces in our northern counties in southern Illinois and southeast Missouri. Any snow in April is very rare, and if we do see some light accumulations that will be even rarer. Along with the possible snow, we are tracking very cold air Wednesday morning and again Thursday morning. Temperatures will be cold enough to cause a freeze in parts of the Heartland and frost possible too both mornings. Near record lows likely both mornings.