There are three cloud types that count as a ceiling: OVC – overcast clouds. BKN – broken clouds. VV – vertical visibility.
For aviation, the altitude of cloud base for the lowest cloud with coverage ≥ 5 oktas (i.e. lowest broken or overcast clouds) is considered the ceiling (see Learning Goal 1d).
Definitions. The height above the ground or water of the base of the lowest layer of cloud below 6000 meters (20,000 feet) covering more than half the sky.
When Federal Air Regulations refer to “ceilings” for weather minimums, the FAA defines a ceiling as: “The height of the lowest layer of clouds above the surface that are either broken or overcast, but not thin.” But since METAR and SPECI observations don’t include the term “thin,” anything reported as broken or …
We also use terminology to convey generally how cloudy it is, for example scattered cloud refers to 3 to 4 oktas where about half the sky is covered, broken cloud is 5 to 7 oktas where much of the sky is covered and overcast is 8 oktas of cloud with no breaks in the cloud at all.
Simply put, a cloud base is the bottom of a cloud layer of any size. A cloud ceiling is the height of the first cloud layer that constitutes at least a broken layer.
IFR means a ceiling less than 1,000 feet AGL and/or visibility less than three miles. Low IFR (LIFR) is a sub-category of IFR. VFR means a ceiling greater than 3,000 feet AGL and visibility greater than five miles.
Cloud layers, of whatever type, are always given with altitude of the bottom of the layer, measured in feet AGL. The last two cases, broken and overcast, describe a cloud layer that may not be penetrated in VFR flight. The bottom of such a layer constitutes a ceiling for VFR flight.
“Scattered” clouds (3/8 to 4/8 cloud coverage) correspond to a partly cloudy or partly sunny sky, with “broken” clouds (5/8 to 7/8 cloud coverage) describing a partly cloudy or partly sunny (5/8 coverage) to mostly cloudy (6/8 to 7/8 coverage) sky.
Ceiling is a term used to describe the base of the lowest cloud layer in the sky and it’s one piece of information that both pilots and meteorologists use when describing the current weather conditions and a vital tool for both fields.
Ceiling- The height of the lowest layer of clouds, when the sky is broken or overcast.
A part of a building which encloses and is exposed overhead in a room, protected shaft or circulation space. (The soffit of a rooflight is included as part of the surface of the ceiling, but not the frame. An upstand below a rooflight would be considered as a wall.)
Definitions of low-ceilinged. adjective. having a lower than normal ceiling. Synonyms: ceilinged. provided with a ceiling especially the overhead interior surface.
Re: *Low Ceiling”
Either Boston or the airport your aircraft came from probably had low ceilings (low clouds) or visibility that required increased spacing between aircraft and that caused your flight to be delayed.