Introducing Risk-Tiered Weather Alerting in Canada

Environment and Climate Change Canada’s (ECCC) Meteorological Service of Canada (MSC) is planning to change to use a tiered alerting service to warn Canadians about expected hazardous weather. The aim is to improve communication by using simple escalating colour levels to provide high-glance value risk information on the expected severity of impacts of a weather event. A three-tier system, based on a risk matrix of impact vs. confidence, was chosen with alerts presented to the public colour-coded as yellow, orange or red.

As part of this warning modernization, the MSC is also introducing impact-informed hazard thresholds, to align with recommendations from the World Meteorological Organization (WMO) to move towards Impact-based Forecast and Warning Services. MSC forecast guidance will shift away from prescriptive geographically-based criteria thresholds towards hazard ranges associated with general potential impacts, grouped into moderate, high and extreme impact categories. Forecasters will incorporate an impact assessment into their alerting workflow and have the flexibility to take known vulnerabilities into account in their warning decisions.

Alert colour level will be included in new alert titles, displayed on MSC’s visual dissemination platforms and used to prioritize alerts. Externally available warning XML files (Common Alerting Protocol – Canadian Profile) will include new colour data for use by third parties to allow for consistent alert level messaging.

This presentation will review the changes being planned to the MSC warning program to include colour based impact-informed tiers in Canada’s weather warning program and the ECCC dissemination platforms.