Record cold causes evaporation fog along the Niagara River

Posted at 2:53 PM, Nov 13, 2019

Cold air blanketed WNY Wednesday morning as temperatures dropped to record levels. Just before 7AM the Buffalo Airport recorded a temperature of 14F at the same time our SkyWatch7 picked up on a neat weather phenomenon.
Evaporation fog was taking place before our very eyes on SkyWatch 7!

The time-lapse shows the air right above the surface of the Niagara river being brought up to the dew point temperature. The saturated air condenses and forms tiny droplets which takes on the appearance of a cloud right above the ground (aka fog) and takes flight!

This process is called evaporation fog or steam fog. Essentially, moisture from the water evaporated into the cold air and because the river is much warmer, the air right above the river warmed up too, the temperature rose to the dewpoint temperature and bam, you have fog! You can see the fog billowing above the river . Once it reaches a height where the the air no longer is saturated the fog dissipates. Then, as the temperatures began to rise past 8AM and the ground began to warm up the environment for fog development ended.