Freezing temperature makes the river smoke

Cold triggers steam fog

Steam fog over the river formed Wednesday morning after cold air moved over warm water.
Steam fog over the river formed Wednesday morning after cold air moved over warm water. (wjxt)

Many rivers and lakes had what looked like smoke emanating from the water Wednesday morning during the first freeze of the season.

People sent in photos of the frost as the temperature dropped to 28°F in central Duval county. One picture showed what is called steam fog over the river.

The big temperature contrast between air and water formed the fog.

Gaseous water in the sky called water vapor condensed into tiny water droplets as it lifted into the cold air above the milder 65 water temperature.

The 35° contrast between air and water temperature rapidly condenses water vapor into steam fog over the moist water bodies.

The phenomenon is also called sea smoke or steam mist and is most common in our area on cold autumn mornings when very cold air drifts across relatively warm water.

By the way, it is different from the common sea fog we get in the spring when warm moist air moves over the chilly Atlantic.

December 2, first freeze. Frost in bird bath, Ponte Vedra Beach, and frosty field, Fernandina Beach, Florida

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