Improved winter weather predictions possible thanks to scientific breakthrough
Release Date 29 July 2020
Advanced warnings of severe winter conditions in Europe and eastern North America may now be possible thanks to a scientific breakthrough.
A team including scientists from the University of Reading found that pressure patterns in the North Atlantic, the key driving force behind winter weather on both sides of the ocean, can be predicted more accurately than previously thought.
Published in Nature today (Wednesday 29 July), the study analysed six decades of climate model data and suggests decadal variations in the atmospheric pressure patterns, known as the North Atlantic Oscillation, are highly predictable, enabling advanced warning of whether winters in the coming decade are likely to be stormy, warm and wet or calm, cold and dry.
However, the study revealed that this predictable signal is much smaller than it should be in current climate models. Hence 100 times more ensemble members are required to extract it, and additional steps are needed to balance the effects of winds and greenhouse gases.
The team showed that, by taking these deficiencies into account, skilful predictions of extreme European winter decades are possible.
Dr Jon Robson, co-author of the study form the Department of Meteorology at the University of Reading, said: "Our research focused on the potential for improved predictions of how much rain we can expect over the coming decade, but the applications could be much broader. For example, understanding how winter winds may change would benefit the planning and development of renewable energy networks, while predicted the impact on the wider Atlantic Ocean helps inform ecosystem and fishery management.
“Predictions of decade-to-decade changes cannot tell us about any specific severe weather event or how a particular year in the future will turn out. However, we can potentially predict the likelihood of extreme winters, say a warm and wet winter opposed to a cold and dry one, occurring in the UK.”
Lead author Dr Doug Smith, who heads decadal climate prediction research and development at the Met Office Hadley Centre, said: “The message from this study is double-edged: climate is much more predictable than we previously thought, but there is a clear need to improve how models simulate regional changes.”
Advance warning of severe winter weather is imperative to those who make risk-based decisions over longer timescales. For example, better forecasts can help the Environment Agency plan water management and flood defences, insurance companies plan for the changing risks, the energy sector to mitigate against potential blackouts and surges, and airports plan for potential disruption.
Improving model simulations will enhance the UK’s response, resilience and security against the effects of extreme weather and climate change – influencing future policy decisions to protect people’s lives, property and infrastructure.