In monitoring severe weather the following terminology may be a useful guide.
ADVISORY - Actual or expected weather conditions may cause inconvenience or concern but do not pose a serious threat.
WATCH - Conditions are favourable for the development of severe weather.
WARNING – Severe weather is occurring or is highly probable. Weather warnings may be issued from six to twelve hours in advance. Severe thunderstorm or tornado warnings are sometimes issued as little as one hour or less in advance. Weather warnings may be issued for thunderstorms, tornados, freezing rain, frost, wind, dust-storm, blizzards, heavy snowfall, winter storms, wind chill.
Western has a weather siren on campus, to warn community members of tornado warnings or imminent weather emergencies. When the siren sounds, everyone should seek shelter immediately.