The propagation of air pressure and wind systems along the South African coast

Large-scale weather systems move over South Africa in a west to east direction, with considerable modifications occurring over the land - sea boundary. This analysis makes use of air pressure and wind data from six sites around the South African coast in order to identify characteristics of this movement. Air pressure variations were found to be highly correlated at all sites. Major-axis wind components were oriented parallel to the coastline, and were not as highly correlated. The air pressure systems are shown to propagate much faster than the wind systems, raising questions about the relationship between wind and pressure, and particularly whether geostrophy applies.