Abstract/Summary

The winter season of 2013/2014 was the stormiest on record for the British Isles. In this article we show that there was an unprecedented amount of cyclone clustering during this season, corresponding to an average of one intense cyclone affecting the country every 2.5 days. An intensely clustered period from 6 to 13 February 2014 that was associated with one specific cyclone family is analysed in detail. This cyclone family is shown to be associated with a strong and straight upper level jet that is flanked by Rossby wave breaking on both its northern and southern sides for the duration of the clustering event. This mechanism is also identified for other periods in this season. The persistence of these conditions resulted in the clustered cyclone activity, and it was accompanied by record-breaking rainfall, widespread flooding and large socio-economic losses.