Exploring the Usability of Probabilistic Weather Forecasts for Water Resources Decision-Making in the United Kingdom

Abstract

Over the last two decades, probabilistic weather forecasts have been developed to quantify the uncertainties inherent in modeling the climate system. The skill of these forecasts has steadily increased, but the question of whether they are usable for water resources management remains open. The interdisciplinary study described in this paper combined a modeling approach with qualitative methods to identify technical and nontechnical factors that enhance or constrain the usability of probabilistic weather forecasts for reservoir management, using a case study of drought management decision-making by a water supply company in northwestern England. The modeling approach calibrated and applied probabilistic medium- and extended-range precipitation forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) to a simplified water resources system to study the technical quality of the forecasts that, in principle, could have informed management decisions during a drought event in 2010. The qualitative approach comprised initial semistructured interviews with water managers and regulators and follow-up discussions using the model experiment results to elicit further insights into the potential for incorporating probabilistic forecast information into decision-making processes. The technical analysis showed that even these postprocessed forecasts did not have skill beyond the medium range; this constrains the type of management decisions the forecasts can inform. Regulatory frameworks and attitudes to risk in the water sector also inhibit the take-up of probabilistic forecasts for drought management decisions owing to the high stakes of such decisions and considerations spanning entire water resource zones.

Seasonal forecasts offer economic benefit for hydrological decision making in semi-arid regions

“…This study addresses the crucial question of whether proactive drought- and extreme event preparedness as well as risk mitigation in water management could be provided by the use of seasonal climate forecasts. Decision makers still hesitate to use seasonal forecasts 9 , 10 . They claim a lack of confidence and credibility due to their probabilistic nature and consequent uncertainties 10 , 11 .…”

“…Decision makers still hesitate to use seasonal forecasts 9 , 10 . They claim a lack of confidence and credibility due to their probabilistic nature and consequent uncertainties 10 , 11 . No explicit action plans could have been developed on the basis of those forecasts and the conservative decision making environment further impeded their use 10 – 12 .…”

“…They claim a lack of confidence and credibility due to their probabilistic nature and consequent uncertainties 10 , 11 . No explicit action plans could have been developed on the basis of those forecasts and the conservative decision making environment further impeded their use 10 – 12 . The debate about the value of seasonal forecasts already started in the 1970s when the provision of seasonal climate forecasts emerged 13 , and still continues, as the optimal use and value of these forecasts is still unclear 9 , 10 , 14 .…”

“…No explicit action plans could have been developed on the basis of those forecasts and the conservative decision making environment further impeded their use 10 – 12 . The debate about the value of seasonal forecasts already started in the 1970s when the provision of seasonal climate forecasts emerged 13 , and still continues, as the optimal use and value of these forecasts is still unclear 9 , 10 , 14 . To implement and foster the usage of seasonal forecasts, the concrete economic benefits need to be demonstrated when decisions and actions are forecast-based.…”

Climate change reception studies in anthropology

“…From the 1990s, such work marked a shift in focus from concerns with local impacts towards more engagement with global information flows and the different ways of knowing that constitute “ethnometeorology” and “western science” (Cruikshank, 2006; Orlove et al, 2002; Peterson & Broad, 2009, p. 75). With increasing scientific understanding of the role of the El Niño Southern Oscillation (ENSO) and associated improvements in the skill of seasonal climate forecasts, anthropologists have worked alongside meteorologists, policy scholars, hydrologists, agronomists and modelers to explore the social/institutional factors affecting access to and use of climate predictions (e.g., Broad et al, 2007; Crane et al, 2010; Lopez & Haines, 2017; Orlove et al, 2004; Pennesi, 2011; Peterson et al, 2010; Rayner et al, 2005; Roncoli, 2006; Taddei, 2013). These studies have exposed social, cultural, and political factors that underpin the reception of climate information, highlighting themes of risk perception, trust, (in)equity, authority, and accountability.…”