A rare wave-like cloud formation rolled across the sky over Hong Kong’s Victoria Harbor in late October; Its wavy curves took on shades of gold and pink amidst the glow of the setting sun.

The Hong Kong Observatory shared the image on social media on Sunday, saying the short-lived atmospheric phenomenon is known as ripple cloud formation.

The photo received at least 200 “likes” within the first two hours of being shared on social media; some described this natural phenomenon as “stunning”.

Fluctus clouds form at the boundary between two air layers with different temperatures and speeds but the same direction of movement, the forecaster said.

The layer of air with slower speed cuts through the layer with higher speed, creating the wavy pattern of the cloud.

The forecaster said Hong Kong will experience another week of fine weather with temperatures ranging between 22 and 29 degrees Celsius (84 Fahrenheit).