RED The surface visibilty is less than 800m or the height above ground level of the Base of the lowest Cloud Layer for 3/8 Cloud (or SCT) or more is below 200ft or the sky is obscured. The height above ground level of the Base of the lowest Cloud Layer for 3/8 Cloud (or SCT) or more is below 200ft or the sky is obscured or the surface visibilty is less than 800m. 7. Red