Gradient wind
The large-scale wind driven by pressure differences between weather systems — the synoptic background flow that everything else rides on top of.
Also known as: synoptic wind, pressure-gradient wind
A gradient wind is air flowing from high pressure to low pressure, deflected by the Coriolis force into clockwise / anticlockwise spirals around the systems. The closer-packed the isobars on the weather chart, the stronger the gradient — and the stronger the wind on the ground.
This is the background wind that frames every forecast:
- Trade winds, prevailing westerlies, and seasonal monsoons are all expressions of the gradient at planetary scale
- Thermal flows (sea breeze, valley breeze, anabatic) sit on top of it — they either add to or fight it
- Terrain-shaped flows (Mistral, Bora, Föhn) start as gradient flow and get accelerated or warped by topography
Reading the gradient first answers most of “what kind of day is this?” If the gradient is strong (over ~20 kt), thermal effects are washed out — the day will run on the synoptic flow. If the gradient is weak (under ~10 kt), thermals and terrain take over. Most days in temperate latitudes sit somewhere between, and the forecast story is which mechanism dominates which hours. Types of Wind walks the full taxonomy.
Related terms
- Trade winds Steady tropical easterlies blowing roughly between 30°N and 30°S — the most reliable wind belts on the planet.
- Sea breeze A daytime onshore wind driven by uneven heating of land and water — the engine of most summer coastal sessions.
- Thermal wind Wind driven by uneven solar heating on a daily cycle — sea breezes, valley breezes, anabatic upslope flow all belong to this family.
- Föhn wind A warm, dry, often gusty downslope wind on the lee side of a mountain range — Föhn in the Alps, Chinook in the Rockies, Halny in the Tatras.