Radiation Fog and Mount Hood

January 15, 2018

Mount Hood with fog

Photographer: Stu Witmer
Summary Author: Stu Witmer

A chilly October morning dawns bright and still over the Sandy River in Oregon. Perfect conditions for radiation fog to form in the river valley. If the air is stable and the sky is clear the land surface will cool overnight. When the dewpoint is reached and if the air becomes saturated, fog will form. This ground-hugging fog disperses when the rising Sun warms the surface. Calm rivers and lakes often produce a robust radiation fog, which is otherwise frequently uneven and patchy. Mount Hood is in the background. Photo taken October 24, 2017.

Photo Details: Camera: Canon PowerShot SX280 HS; Exposure Time: 0.0013s (1/800); Aperture: ƒ/4.5; ISO equivalent: 80; Focal Length: 13.0mm; Software: Adobe Photoshop 7.0.