English Channel Winter Storminess has increased to levels last seen 200 years ago

Abstract Information from a variety of sources has suggested that an increased rate of storminess was experienced across the British Isles in the late eighteenth/early nineteenth century. However, it is not clear how stormy that period was relative to current conditions. Using newly recovered barometric pressure data that extend back to 1748 we show here that winter storminess across the English Channel has increased since the 1870s and has now reached a level that is comparable to that experienced during 1790-1820s. However, the nature of the storm activity was quite different in the two periods: current wind increases are restricted to the winter season and originate from a south-westerly direction whereas elevated storminess in the early period extended to the summer season and the wind direction was more variable. While a strengthened North Atlantic jet stream is implicated in both periods, in the early period it is likely that the storm track shifted slightly to a more southerly location whereas in the most recent period the increases in storminess are associated with an extension of the jet north-eastwards across the British Isles. We discuss the potential forcing mechanisms responsible for the changes in storminess across the region over this multi-century timeframe.