Victoria’s Valley Fog and Arch Cloud Captured by NASA

NASA’s Earth Observatory highlights autumn fog in eastern Victoria as the Terra satellite’s MODIS instrument captures morning valley fog in the Victorian Alps and an arch-shaped cloud drifting over Port Phillip Bay. The piece explains radiation fog forms when air cools to the dew point in calm conditions, sinks into valleys, and lingers where terrain shades the ground; nearby breezes interacting with the bay’s terrain likely shaped the arch cloud, which moved south as the fog faded.