Zonal winds associated with the dry period 1975–76 in England and Wales

Abstract

THE low rainfall in England and Wales during the period May 1975 to August 1976 was discussed by Morris and Ratcliffe¹ and was shown to be associated with a progressive shift northwards in the position of the mean jetstream over the north-east Atlantic during the three successive years 1974–76. We report here that marked circulation changes in the 500-mbar (5.5 km) flow during the dry period occurred both in the vicinity of the British Isles and over the central Pacific. The flow is compared with an analysis of 5-d mean charts exhibiting blocking of the 500-mbar flow in the vicinity of the British Isles and it is suggested that the anomalous displacement of the jetstream during the dry period may have been associated with an eastward surge in the subtropical jet off south-east Asia.