has gloss | eng: A severe thunderstorm watch (SAME code: SVA; sometimes referred to as "blue box" or "yellow box" by meteorologists and storm chasers) is issued when weather conditions are favorable for the development of severe thunderstorms. If the thunderstorms are forecast to be such that there is a significant risk that they may produce tornadoes, then a tornado watch (which also automatically implies a severe thunderstorm watch) is issued. A severe thunderstorm watch can also be upgraded to a tornado watch as conditions warrant (in which case the existing severe thunderstorm watch, or a portion of it, would be replaced). A watch must not be confused with a severe thunderstorm warning. |