n.a
condition in which clouds or
fog are heavy and
close to the
ground, making aircraft takeoffs or landings extremely
dangerous or impossible.
Ceiling refers to the height of the lowest
level of a
bank of clouds as measured from the
ground. When skyward visibility is
limited to 50 feet (15.2 m) or less, it is called ceiling
zero. In contrast, when the sky is
clear it is called
ceiling unlimited.