Definition
Steady surface winds that blow from the northeast toward the southwest in the tropical latitudes of the Northern Hemisphere, roughly between the equator and 30° N. They result from air flowing from the subtropical high-pressure belt toward the equatorial low, deflected to the right by the Coriolis force.
Plain English
A reliable belt of winds in the tropics north of the equator that blow from the northeast. They exist because air moves from higher-pressure areas near 30° N down toward the equator, and the Earth's rotation bends that flow so it arrives from the northeast.
Context Anchor
Seen in weather and wind-circulation discussions, especially when explaining how Earth’s rotation changes wind direction.
Derivation
Called 'trade winds' because their dependable direction allowed sailing ships to follow established trade routes across the Atlantic and Pacific. 'Northeasterly' simply means the wind comes from the northeast. Knowing this helps pilots remember that a wind is always named for the direction it comes from, not the direction it is heading.
Why Pilots Care
They influence crosswinds, fuel planning, and weather systems on flights through tropical regions.
Grounding Statement
Picture air sliding south from about 30° N toward the equator; as it moves, the Earth's rotation curves it to the right, so by the time it reaches the tropics it is blowing from the northeast.
Intuition Check
Do not read northeasterly as “going northeast.” In aviation weather, a northeasterly wind comes from the northeast.
Example Sentence 1
The northeasterly trade winds give the Caribbean its steady easterly flow at low altitudes most of the year.
Example Sentence 2
Before departure the pilot checked how the northeasterly trade winds would affect runway crosswind components.