Some years are memorable for their multiple bad weather events. In the UK, 2007 stands out, for the devastating storm Kyrill in January, followed by torrential summer rain which brought widespread flooding.
The winter of 2013 to 2014 also left its mark, with storm after storm pummelling UK shores, bringing record breaking rainfall and damaging gusts of wind. Hundreds of thousands of homes were left without power over Christmas, and large parts of Somerset were submerged for much of the winter.
Until now, such sequences of events have been considered runs of bad luck, but a new study suggests that their occurrence they might not be random.
John Hillier and his colleagues from Loughborough University have studied meteorological and insurance data going back to 1884, using new statistical techniques to analyse the timings of storms, floods and drought.
They explain in the journal Environmental Research Letters how these seemingly independent events occur together in bad years more often than chance might predict, suggesting an underlying link.
One possible explanation might be that sea surface temperatures or soil moisture hold a long-term “memory”, which helps to drive similar patterns of weather over months or even years.
If they are right, it means that insurers need to adjust their catastrophe models and governments need to rethink their emergency planning. “If both a big flood and winter storm turn up in the same year, how ready are we?” asks Hillier.
