A composite study of early summer squall lines and their environment over West Africa

Summary Composites of synoptic reports and wind observations in a coordinate system moving with the squall lines over the WAMEX area in June 1979 allow us to show the average structure of the airflow, the moisture and temperature fields in the synoptic scale environment of West African continental squall lines.The monsoon front, the African Easterly Jet, the easterly waves, and the squall lines interact and produce the observed air flow patterns. The results of the composite enalysis reveal a northward surge of the monsoonal air masses in the rear of the squall lines thus providing favorable conditions for the generation of new squall lines.With 14 Figures