altostratus

9.9

A gray or blue cloud layer in the middle part of the sky that often covers the whole sky

noun
/ˌæltoʊˈstrætəs/

Specialized

: nube altostrato

As the altostratus clouds spread across the horizon, we knew we would soon experience a change in the weather.

Examples

I saw altostratus forming early in the morning.
Ahead of the storm, a broad sheet of altostratus stretched from horizon to horizon.
Pilots often check for altostratus when determining flight visibility.
The sky was covered by a thick layer of altostratus clouds, blocking the sun.
The sky was covered by altostratus clouds today.
The sky turned gray as an extensive layer of altostratus clouds moved in, signaling the approach of rain.
Looking up, we could see altostratus clouds forming, indicating that the day would become overcast.

Synonyms

altostratus cloud

vsaltostratus

Specialized

8.2

A gray or blue cloud layer in the middle sky that often covers most of it and brings light rain

is the same cloud type but named in a more concise form

Compounds

altostratus cloud

Specialized

8.2

A gray or blue cloud layer in the middle sky that often covers most of it and brings light rain

How Thick

nimbostratus

Specialized

1 8.0

stratus

Specialized

1 5.9

altostratus

Specialized

9.9

cirrostratus cloud

Specialized

7.2

cirrus

Specialized

2 7.0

Surface Forms

altostratus singular

altostratuses plural

altostrati plural

Morphology

altostratus = stratus (semi-transparent) = alto + stratus

Formed from the combining form 'alto-' + 'stratus'; the components are clear to those familiar with meteorological terms, but 'alto' has a different common English sense (a singing voice) and the usage is technical.

Etymology

The word altostratus comes from Latin parts alto- meaning 'high' and stratus meaning 'layer', and you can see the same alto- in altitude. In cloud names alto- usually means 'middle height', so an altostratus is a wide, gray cloud layer that sits in the middle of the sky.