Winter Storm Watch: The National Weather Service issues this when conditions are favorable for a winter storm to begin within 48 hours. Issuance usually occurs at 36-48 hours before the event is expected to begin.

There are three types of alerts that can be issued: a winter storm watch, a winter weather advisory and a winter storm warning

A Winter Storm Watch is put in place when snow, sleet or ice is possible and there is at least a medium confidence in the probability of heavy snowfall, sleet or freezing rain that will have a significant impact. A watch is declared if the criteria is expected to be met within the next 2 to 3 days.

A winter storm watch has been issued by the National Weather Service for much of the Lowcountry heading into this week. The watch is in effect from Tuesday afternoon through Wednesday morning, meaning heavy snow is possible with accumulation totaling one to three inches.