Watch, Warning or Advisory!  What’s the difference?

They are National Weather Service (NWS) terms used when issuing public alerts of impending weather events.  The criteria for issuing Watches/Warnings/Advisories:

• Watches: 50% confidence of meeting Warning criteria.  It is generally within 36-48+ hours.  It is typically issued for a large geographical area.
• Advisories and Warnings: 80% confidence in the event occurrence.  They are generally within 24-36 hours.  They are issued to a more narrow geographical area. An Advisory is in between a Watch and a Warning and the weather event has a pretty good chance of taking place but for less severe conditions. On the other hand a Warning means that the weather event is likely to occur or already in progress.

_{Source: https://www.weather.gov/media/box/officePrograms/box_criteria_thresholds.pdf}