The Tennessee River Gorg Sunrise Cloud Inversion
By Eliot Berz
On a perfect cool night in the Tennessee River Gorge, temperature and humidity work together to set the stage for an awe-inspiring scene that is revealed at daybreak. If the conditions are just right, a river of clouds form just above the water’s surface below the mountains. This mesmerizing weather event is called a cloud inversion.
The topography, river, and our regional climate provide the perfect conditions for regular cloud inversions from spring to fall in the gorge. Although they are by no means a daily occurrence, inversions can be predicted if you know what to look for and understand what causes these events. A quick look over the weather forecast can tell you if an inversion is possible the following morning. Here is what to look for:
1) Temperatures that meet the dew point at daybreak
The dew point is “the temperature the air needs to be cooled to (at constant pressure) in order to achieve a relative humidity (RH) of 100%. At this point the air cannot hold more water in the gas form.” (weather.com).
2) Relatively high humidity
Thanks to the Tennessee River, we have an abundance of humidity within the gorge. This availability of humid air provides moisture that can condense to form clouds.
3) Calm conditions
Too much wind will disperse the clouds and not allow them to settle over the river.
4) No incoming weather fronts
Incoming weather fronts are often not favorable for cloud inversions.
5) Long, cool nights
Long and cool nights help create the conditions for an inversion. Inversions are especially common after long, cool fall nights.