Impact of the Icelandic Low on British climate in winter.

Correlations of the North Atlantic Oscillation (NAO) with climate variables in continental Europe are strong but weak over Britain. This article presents evidence that interannual variations of British climate are explained more successfully by variations of the Icelandic Low (IL), the northern component of the NAO. The IL changes continuously in intensity as well as position, and these variations are not represented in the NAO. Monthly values of intensity and latitude and longitude positions for the IL are estimated from gridded sea level pressure data. These are used to analyse their impact on interannual variations of winter precipitation and temperature over Britain for the period 1981–2014. It is found that the primary influence on the interannual variations of winter precipitation over Britain are the pressure and the longitude position of the IL. When the IL is deeper or situated east of its mean location, there is above normal precipitation over Britain. The primary influence on air temperature is the meridional migration of the IL; it is warmer when the IL is situated north of its mean position. The impact of the IL on precipitation and air temperature are evaluated also for Scotland, North England and South England separately. [ABSTRACT FROM AUTHOR]