DECATUR, Ill. (WAND) - There are a couple of ways heavy snow develops in central Illinois. One of which is called overrunning.

A weather overrunning pattern is a meteorological phenomenon that occurs when warm, moist air advances over a cooler, denser air mass. This setup typically leads to the formation of stratiform clouds and steady precipitation. It often happens in situations like warm fronts or when moist air flows over a retreating cold air mass.

This is exactly the setup taking place this weekend. Moist air from the Gulf "runs" over the top of a warm front situated to our south. As the moist air hits the deeper cold air across the state, snow develops. The worst of which will occur during the daylight hours Saturday.

Stay safe, stay weather-aware and stay tuned for more de

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