Should we really do impact forecasts? Strategic learnings at MeteoSwiss

The shift from traditional weather forecasts to impact-based forecasting (IBF), and similarly, the issuing of warnings based on physical weather forecast thresholds vs. on predicted societal impacts, is often advocated to enhance societal preparedness and resilience. However, changing forecasting and warning paradigms may simply not be possible in the current state of data availability and knowledge, or could interfere with many well-established response routines on which authorities and other key stakeholders rely, if not closely co-produced and monitored. Such consequences demand a careful testing and establishment of this concept, requiring diverse and – often considerably more - resources than may have initially been expected in roll-out plans of IBF services.

At MeteoSwiss, drawing on experiences over the last two years from internal workshops, stakeholder consultations, research projects, and international experiences, we have engaged in a critical reflection on whether and how to integrate impact forecasts into our service portfolio, and what the strategic and operational questions are which need to be clarified to better come to a sensible judgement. This contribution outlines the motivations behind the reflections on how and for whom to provide impact forecasting services, and in what other way(s) we see a national meteorological service contribute to IBF.

We will cover the strategic principles guiding our current decisions, provide some concrete insights on use case explorations, technical advances, and exploratory research results, which have contributed to our current vision and open questions. Rather than offering a binary endorsement or rejection of IBF, we present a set of strategic considerations that can guide NMHSs facing similar dilemmas. By doing so, we contribute to a more nuanced discourse on the promises and pitfalls of impact-based approaches and argue for a context-sensitive, transparent, and participatory path forward.