Evening glory wave-cloud lines in northwestern Australia

Shortly before sunset on 10 November 1983, two spectacular low cloud lines were observed and photographed from a CSIRO research vessel about 50 km offshore, northwest of Port Hedlund in Western Australia. These clouds were similar in ap-pearance to the well-known 'morning glory' cloud lines of the Gulf of Carpentaria region. They were orientated approximately east-west and moved from the south at an estimated speed of close to 10 m s-1. An analysis of available meteorological data suggests that the clouds were associated with a bore-like disturbance which was gener-ated by the interaction of a thunderstorm gust front with the sea breeze front and which propagated on a waveguide provided by the low-level stable layer capped by a deeper adiabatic layer.