Aviation Weather

full text of the classic FAA guide

LOW STRATUS CLOUDS

Stratus clouds, like fog, are composed of extremely small water droplets or ice crystals suspended in air. An observer on a mountain in a stratus layer would call it fog. Stratus and fog frequently exist together. In many cases there is no real line of distinction between the fog and stratus; rather, one gradually merges into the other. Flight visibility may approach zero in stratus clouds. Stratus tends to be lowest during night and early morning, lifting or dissipating due to solar heating during the late morning or afternoon. Low stratus clouds often occur when moist air mixes with a colder air mass or in any situation where temperature-dew point spread is small.

Table of Contents
Previous Section: Fog
Next Section: Haze and Smoke

A PDF version of this book is available here. You may be able to buy a printed copy of the book from amazon.com.