A watch and a warning are two different types of alerts issued by the National Weather Service (NWS) for severe weather conditions. A watch is issued when the conditions are favorable for a certain type of severe weather to occur, while a warning is issued when the severe weather is imminent or already occurring. In other words, a watch alerts the public to be prepared for severe weather, while a warning indicates that they should take immediate action.
A watch or warning may be issued for a variety of severe weather conditions, including thunderstorms, tornadoes, severe winter storms, floods, and hurricanes. Watches are generally issued several hours before a storm is expected to strike, while warnings are typically issued shortly before the storm is expected to hit. Watches may be upgraded to warnings if the storm becomes more severe than expected.