Defining the impact of weather

Forecasters, researchers, modelers, managers, etc. are being asked to focus their efforts on “High-impact weather.” Exactly what high-impact weather is has been a topic of debate for the last few years. Without a clear understanding of the definition of high-impact weather, the planning and development of priorities, the allocation of resources, the defining of forecaster roles, and the day-to-day production of forecasts and warnings cannot be effectively accomplished.

This document outlines a new approach to defining the impact of weather. By examining the factors that produce the weather's impact, whether it is the characteristics of the event itself, who/what is being impacted, and the capacity to mitigate the impact, this document outlines a broader range of impact types. These are:

Low-impact – minor inconvenience, small and local economic losses, etc. Moderate-impact – minor damage, some social disruption, etc. High-impact – damage, risks to health, broad economic impact, etc. Extreme-impact – Catastrophic losses, deaths, injuries, major social disruption

The impact of weather is applied to economic sectors, people, society, and the environment to determine the characteristics of each category. This approach also suggests a tiered method of alerting the end user to the various levels of weather impact. This is discussed briefly in the presentation.