Funnels are persistent, while scud usually dissipates or changes rapidly. In certain cases, shafts of virga may precede a downburst. A NWS product indicating that a particular weather hazard is either imminent or has been reported. A warning indicates the need to take action to protect life and property. The type of hazard may be a tornado, severe thunderstorm, flood, or flash flood.
Warnings typically cover periods of an hour or less for only one county.
A watch is a recommendation for planning preparation, and increased awareness. Watches typically cover periods of 6 to 12 hours for many counties. Watches are issued for tornadoes, severe thunderstorms, floods, or flash floods.