CORPUS CHRISTI, Texas — Sea fog forms mainly in colder seasons, when sea surface temperatures are low and warm, humid air passes over the ocean surface. It is a low visibility hazard both to marine navigation and to coastal motorists. Sea fog can drop visibility from unlimited to just a few yards in moments whether on a boat or driving a car.
It is an easily foreseen weather phenomenon, so careful attention should be paid to your weather forecast. In the event of expected sea fog, your National Weather Service will issue a Dense Marine Fog Advisory.
Typically in the winter and early spring, periodic cold fronts move over sea waters, such as the Gulf of Mexico, and the cold air gradually cools the upper portion of the water.
As the cold air retreats, warmer and more humid air passes over the chilled water.
The interaction between ocean and atmosphere cools the lowest part of the air to its dewpoint, causing the air to saturate and fog to form.
Onshore flow carries the sea fog to adjacent coastal areas, where it can drop visibility to near zero in short order. The fog can thin or dissipate as the atmosphere heats or when a cold front replaces the warm, humid air with dry Polar air.