June circulation

[xmetman]

The changes in the circulation pattern over western Europe and the eastern Atlantic during June are well captured in these three 10 day mean pressure charts. The change from an anticyclonic NE’ly transitioning through a cyclonic and then into a mobile westerly are easy to see. A large area of positive mean sea level pressure [MSLP] anomalies of +15 hPa dominated the first 10 days over  and to the NE of Iceland, that gave way to a discrete -1o hPa negative anomaly over the British Isles during the middle of June, before negative anomalies of -9 hpa and lower, became established over Iceland, a complete reversal of MSLP anomalies that existed for the first 10 days of the month!