New colours for weather alerts signal potential impacts

Environment Canada now uses yellow, orange and red for warnings, advisories and watches to indicate likely effects; a recent snowstorm put the Greater Toronto Area and Ottawa under an orange alert.

A snowstorm brought heavy snowfall to parts of southern Ontario and coincided with orange alerts issued by Environment Canada. The agency introduced a colour-based system in November that attaches a colour to each type of weather alert. The three colours — yellow, orange and red — are meant to communicate not only the expected weather but also the likely effects on people, property and communities. The system uses examples such as windstorms to illustrate typical impacts for each colour. What the colours mean: - The system attaches yellow, orange and red to warnings, advisories and watches to indicate impact levels. - Yellow alerts describe impacts that could be moderate, localized and short-term, for example short-term utility outages or risk of injury from falling branches. - Orange alerts indicate likely significant damage, disruption or health impacts that can be major, widespread or last a few days; the Greater Toronto Area and Ottawa were under orange alerts during the recent snowstorm. - Red alerts are issued when weather is very dangerous and possibly life-threatening, with the potential for extensive, widespread and prolonged impacts and only when forecast confidence is very high. - Environment Canada used windstorms as examples to explain typical effects under each colour. Summary: The colour system is intended to help people more quickly understand the potential impacts of weather alerts, and it was in effect during the recent southern Ontario snowstorm. Undetermined at this time.