Oral presentation: Cees van Westen

Small Island Developing States in the Eastern Caribbean face escalating hurricane risk under climate change. Anticipatory Action mechanisms offer a means to translate advances in climate and weather prediction into timely, risk-reducing interventions. However, designing robust, decision-relevant trigger models that balance forecast skill, uncertainty, and operational feasibility remains a key challenge, particularly in multi-country contexts.

We studied the feasibility of a sub-regional Early Action Protocol (EAP) covering Saint Kitts and Nevis, Dominica, and Antigua and Barbuda, and focused specifically on how to design a sub-regional trigger model. Using stakeholder consultations, analysis of national disaster management systems, analysis of historical and synthetic events by modelling wind, surge, and rainfall, and a review of existing forecasting products, we assessed trigger options across temporal scales, compound-hazard components, and impact relevance.

Results show that the wind and track forecasts from the US National Hurricane Centre demonstrated substantial improvements in accuracy over recent decades. Early actions within this lead time may include mobilising communities and prepositioning stock.

Our study highlights key design principles for anticipatory trigger models in SIDS now and in the future: transparency, simplicity, tolerance to forecast uncertainty, and alignment with decision timelines for early action. By articulating how forecast information can be operationalised across borders, this contribution advances the integration of climate services and anticipatory humanitarian action in highly exposed island regions. A sub-regional trigger model can leverage shared meteorological information and pooled technical expertise.

The project was cofunded through the EU HORIZON Europe PARATUS project.