Toward usable predictive climate information at decadal timescales

Decadal climate predictions provide information out to the 10-year timescale, bridging the gap between seasonal and climate projections. This paper presents an interdisciplinary research framework to develop credible and use-relevant decadal climate predictions. We focused on case studies of flood risk and water resource management in Colorado and California. Climate- and stakeholder-oriented research streams iterate and build on each other, coming together over time to inform the development of decadal prediction images. These images are discussed with stakeholders to identify potentially usable formats and the decisions they may inform. Several potentially usable formats are identified: predictions alongside projections, predictions relative to historical climate, multivariate information, and information at the weather scale and in terms of hydrologic impacts. These image formats are potentially usable for climate adaptation planning and testing, public messaging, and justification of long-term investments and to engage policy makers around objectives. We conduct a critical review of the framework as implemented here and discuss its general applicability to other climate regions and decision contexts.