Changing regional climatic gradients in the United Kingdom

The regional climatic gradient between the north‐west and south‐east of the United Kingdom is analysed in the context of the fluctuating vigour of the mid‐latitude westerlies. The study period comprises the mid‐twentieth century period of atmospheric blocking and the more active westerlies that have characterized much of the 1980s and 1990s, especially in Winter. This change has coincided with increased regional gradients of rainfall, temperature and sunshine between north‐western and south‐eastern Britain. This is consistent with an enhanced climatic gradient across Europe and it is suggested that this may have been accentuated across the United Kingdom by orographic influences. These results also show some congruence with scenarios of climate change for the twenty‐first century, indicative of the sensitivity of the North Atlantic Oscillation (and mid‐latitude westerlies) to temperature change. This could contribute to a significant hydrological and environmental perturbation when viewed in the context of increasing demand for water in southern and eastern England.