altocumulus cloud
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Definition
- Noun:
- A mid-level cloud formation: An altocumulus cloud is a type of cloud belonging to the middle cloud family, typically found at altitudes between 6,500 and 20,000 feet (approximately 2 to 6 kilometers).
- Characteristic appearance: It appears as a layer or patch of white or gray clouds, composed of rounded masses or rolls, often arranged in groups, lines, or waves across the sky.
Usage
- Altocumulus clouds are often indicators of atmospheric instability at mid-levels.
- They are primarily composed of water droplets and can sometimes contain ice crystals.
- Observing altocumulus clouds can help in short-term weather forecasting.
Examples
- Noun:
- The sky was dotted with a fleet of altocumulus clouds this morning.
- Meteorologists noted that the altocumulus cloud layer suggested a change in the weather pattern.
- The altocumulus cloud formation created a beautiful, textured pattern against the blue sky.
Advanced Usage
- "Altocumulus castellanus": A specific subtype where cloud towers rise from a common base, resembling castle battlements. This type often indicates greater instability and can precede thunderstorm development.
- The presence of altocumulus castellanus suggested the possibility of afternoon thunderstorms.
- "Altocumulus lenticularis": A lens-shaped, stationary subtype often formed by mountain waves, sometimes mistaken for "flying saucers".
- The altocumulus lenticularis clouds remained fixed over the mountain peak.
Variants and Related Words
- Altocumulus (n): The standard, shortened form of "altocumulus cloud". Often used interchangeably in meteorological contexts.
- The forecast calls for altocumulus and high winds.
- Ac (abbreviation): The standard meteorological abbreviation for altocumulus clouds.
- The weather map showed a large area marked 'Ac'.
Synonyms
- Mid-level cumuliform cloud: A descriptive synonym emphasizing its form and altitude.
- Sheepback cloud: An informal, descriptive term sometimes used due to its woolly, flocked appearance.
Related Phrases
- A mackerel sky: A common phrase describing a sky filled with altocumulus clouds in a pattern that resembles fish scales, often a sign of an approaching warm front.
- "Mackerel sky, mackerel sky, never long wet and never long dry," is an old saying referring to altocumulus clouds.
Noun
- a cumulus cloud at an intermediate altitude of 2 or 3 miles