easterly wave
C1/C2Technical / Scientific (Meteorology, Climatology)
Definition
Meaning
A north-south trough of low atmospheric pressure that moves from east to west in the tropics, often serving as an initial disturbance for tropical cyclone development.
In broader meteorological parlance, any westward-propagating wave disturbance embedded within the easterly trade winds, typically characterized by enhanced cloudiness and rainfall.
Linguistics
Semantic Notes
A precise technical term; its core meaning is distinct from general directional terms 'easterly' and 'wave'. It denotes a specific, observable meteorological phenomenon.
Dialectal Variation
British vs American Usage
Differences
No significant differences in definition or usage. Both UK and US meteorological communities use the term identically.
Connotations
Technical, neutral, precise.
Frequency
Virtually unused outside of meteorology, climate science, and weather forecasting contexts in both regions.
Vocabulary
Collocations
Grammar
Valency Patterns
The easterly wave [verb, e.g., developed, intensified, moved] over the Atlantic.Forecasters are watching [determiner, e.g., the, an] easterly wave.Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “None. It is a technical term with no idiomatic usage.”
Usage
Context Usage
Business
Not applicable.
Academic
Primary usage. Common in meteorology, geography, and environmental science research and textbooks.
Everyday
Extremely rare, used only in detailed weather reports during hurricane season.
Technical
The standard context. Used in weather models, satellite analysis, and forecast discussions.
Examples
By Part of Speech
verb
British English
- The system began to easterly wave its way across the basin. (Very rare, non-standard)
American English
- The system began to wave eastwardly across the basin. (Rare, awkward)
adverb
British English
- The system moved easterly-wave-like across the ocean. (Extremely rare, non-standard)
American English
- The system moved like an easterly wave across the ocean.
adjective
British English
- The easterly-wave disturbance was being closely monitored.
American English
- The easterly wave disturbance was being closely monitored.
Examples
By CEFR Level
- (Not applicable for A2 level)
- (Rarely used at this level. Possible example: The weather report mentioned an 'easterly wave' that could bring rain.)
- Satellite imagery clearly showed the easterly wave emerging off the coast of Africa.
- Forecasters noted that the easterly wave was becoming more organised.
- The genesis of Hurricane Fiona was traced back to a vigorous easterly wave that crossed the Atlantic.
- Numerical models disagreed on the potential for cyclogenesis within the easterly wave.
Learning
Memory Aids
Mnemonic
Think of a 'wave' in the easterly winds. Picture weather maps showing a wavy line of clouds moving from the east across the Atlantic.
Conceptual Metaphor
THE ATMOSPHERE IS A FLUID (carrying waves of disturbance).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Direct translation ('восточная волна') is possible but may sound like a poetic or general directional description unless specified as a meteorological term ('тропическая волна', 'тропическое возмущение').
Common Mistakes
- Confusing it with a 'tsunami' or 'tidal wave'.
- Using it to describe any wind coming from the east.
- Capitalising it as a proper noun (it is not).
Practice
Quiz
What is an 'easterly wave' primarily associated with?
FAQ
Frequently Asked Questions
No. An easterly wave is a disturbance that can serve as a seedling for a hurricane, but most easterly waves do not develop into tropical cyclones.
They frequently originate over North Africa and move westward over the tropical Atlantic Ocean, though they can occur in other tropical basins.
Not directly as a distinct sensation. You would experience its effects as a period of increased cloudiness, showers, and thunderstorms.
Because it appears as a wavelike perturbation or trough in the atmospheric pressure and wind fields when plotted on weather maps.