Abstract: An elongate weather louvre 10 includes a leading longitudinal edge 12, a trailing longitudinal edge 14, and a crown portion 16 on a flow path defined between the leading longitudinal edge 12 and the trailing longitudinal edge 14. Also included is an intermediate portion 18 between the leading longitudinal edge 12 and the crown portion 16. The intermediate portion 18 has a leading surface 20 and a ramped projection 22 forming part of the leading surface 20 configured to direct airflow at least one of towards and over the crown portion 16.