A storm watch is issued when there is a potential for a severe thunderstorm, tornado, or hurricane in an area. It is a notification that conditions are favorable for the development of hazardous weather in a given area. A storm warning is issued when a severe thunderstorm, tornado, or hurricane is imminent or already occurring in an area. It is a notification that hazardous weather is occurring or about to occur in a given area.

The main difference between a storm watch and a storm warning is that a storm watch is issued when hazardous weather is possible, while a storm warning is issued when hazardous weather is occurring or about to occur. A storm watch gives people time to prepare, while a storm warning should be taken more seriously and prompt people to take immediate action.