A city photographer captured a rare cloud formation in the Hong Kong skies last month, which the Hong Kong Observatory shared on its social media pages on Monday. The fluctus cloud formation — also called ‘breaking waves’ clouds because of its wave-like appearance — was seen in a photograph taken at Tai Mo Shan that the meteorological body shared to show beams of sunlight piercing through clouds and the rolling hills of Hong Kong.
While other photographers shared images of what the observatory has called ‘cloud gap light’, none of them were able to capture the fluctus, which is difficult to do as it typically lasts only a minute or two, therefore making it hard to spot. It is formed when two different layers of air with different temperatures and speeds come together, causing the upper layer to ripple and curl like waves. This results in a series of vortices that create the crashing-wave appearance of the cloud.
Last summer, the observatory shared another image of a fluctus formation that was taken over Victoria Harbour. An eagle-eyed photographer also took pictures of lenticular clouds, also known as flying saucer clouds, over the harbour in August 2023 — an unusual occurrence as they are not usually seen in the summer.
Header image credit: Leung Yu Po via Hong Kong Observatory