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.