What does steam fog typically indicate when flying?

Steam fog is a phenomenon that occurs when cold air moves over warmer water. This typically happens under stable atmospheric conditions where the air is calm. The presence of steam fog indicates that the air at the water's surface is being saturated due to the warmth of the water, leading to the formation of condensation as the cooler air moves over it.

In the context of aviation, the occurrence of steam fog often signals the possibility of convective turbulence in the immediate area. This is because the inversion layer that can form with stable conditions may be disrupted, leading to unstable air and potential turbulence as thermal energy tries to mix.

Therefore, the indication of convective turbulence is vital for pilots, as it signifies that while the surrounding air may appear calm, there can be unpredictable air movements just above the surface, potentially hindering safe flight operations.