altocumulus: meaning, definition, pronunciation and examples
C2Technical/Scientific
Quick answer
What does “altocumulus” mean?
A type of mid-level cloud that appears as white or grey patches or layers with a wavy, rounded, or lumpy appearance.
Audio
Pronunciation
Definition
Meaning and Definition
A type of mid-level cloud that appears as white or grey patches or layers with a wavy, rounded, or lumpy appearance.
In meteorology, a cloud genus belonging to the middle étage, typically found between 2,000 and 7,000 metres (6,500–23,000 ft), composed of water droplets and sometimes ice crystals, often indicating fair weather but can precede a change.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Spelling is identical. Pronunciation may show minor accent variations.
Connotations
Identical technical connotations in both varieties.
Frequency
Equally low-frequency and specialised in both UK and US English, used almost exclusively in technical domains.
Grammar
How to Use “altocumulus” in a Sentence
The [sky/forecast] featured [adjective] altocumulus.Pilots reported [type of] altocumulus at [altitude].Vocabulary
Collocations
Examples
Examples of “altocumulus” in a Sentence
adjective
British English
- The altocumulus formations were particularly well-defined that afternoon.
American English
- We studied the altocumulus cloud deck in our meteorology lab.
Usage
Meaning in Context
Business
Virtually never used.
Academic
Used in meteorology, atmospheric science, geography, and aviation textbooks and papers.
Everyday
Extremely rare. Might be used by weather enthusiasts or pilots in conversation.
Technical
Standard term in meteorological reports, aviation weather briefings (METAR/TAF), and scientific literature.
Watch out
Common Mistakes When Using “altocumulus”
- Mispronouncing as 'alto-cumulous'.
- Confusing it with 'cirrocumulus' (higher) or 'stratocumulus' (lower).
- Using it as a general term for any puffy cloud.
FAQ
Frequently Asked Questions
Typically, no. Standard altocumulus clouds are composed of water droplets and rarely produce precipitation that reaches the ground. However, some species like altocumulus castellanus can indicate instability and potential for thunderstorm development later.
Altitude and apparent size. Cirrocumulus clouds are higher (above 6,000m/20,000ft) and are composed of ice crystals, making their cloud elements appear much smaller. A common rule of thumb is that if you can cover an individual cloudlet with three fingers at arm's length, it's likely altocumulus; if it's the size of a fingernail, it's cirrocumulus.
It would sound highly technical and unusual. In everyday talk, people would simply say 'puffy mid-level clouds' or describe the sky's appearance (e.g., 'a mackerel sky').
In meteorological codes and aviation weather reports (METAR), it is abbreviated as 'Ac'.
A type of mid-level cloud that appears as white or grey patches or layers with a wavy, rounded, or lumpy appearance.
Altocumulus is usually technical/scientific in register.
Altocumulus: in British English it is pronounced /ˌæl.təʊˈkjuː.mjə.ləs/, and in American English it is pronounced /ˌæl.toʊˈkjuː.mjə.ləs/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think 'alto' (like a high singing voice) + 'cumulus' (fluffy heap clouds). So, it's a 'high heap' cloud.
Conceptual Metaphor
CLOUDS ARE TEXTURES/LAYERS (e.g., a blanket, a patchwork, a ripple).
Practice
Quiz
At what approximate altitude range is altocumulus typically found?