Watch vs Warning
Based on information provided by NOAA (National Oceanic and Atmospheric Administration), please be aware of the following distinctions.
A thunderstorm is a rain shower during which you hear thunder. Since thunder comes from lightning, all thunderstorms have lightning.
A thunderstorm is classified as "severe" when it contains one or more of the following: Hail (one inch or greater), Winds in excess of 58 mph, Structural wind damage or a tornado.
A severe thunderstorm watch means that the potential exists for the development of thunderstorms which may produce large hail or damaging winds. A watch is issued by the SPC (Storm Prediction Center).
A severe thunderstorm warning means that a severe thunderstorm is occurring or is imminent based on Doppler radar information or a reliable spotter report. A warning is issued by the local National Weather Service.