Open three forecast apps for the same beach and you might see three different wind directions for the same hour. That’s not the apps lying — that’s wind being more than one thing at once. Some of what you ride is global air slowly circling the planet. Some of it is local air falling down a mountain. Some of it didn’t exist an hour ago.

If you understand the types of wind — what drives each one and how they stack — your forecast goes from a number you stare at to a story you can read. Here’s the rider’s tour, from the planet-scale stuff down to the gusts that didn’t exist this morning.

Wind in one line

Wind is air moving from high pressure to low pressure, deflected by the Earth’s spin. That’s it. Every type below is a variation on that theme — different scales, different drivers, different shapes.

The driver matters because it tells you whether the wind will hold, build, swing, or die. A trade wind blows for weeks. A thunderstorm gust front blows for fifteen minutes.

Pressure-driven winds (synoptic)

The big stuff: continental-scale weather systems with names like high and low. Air flows out of highs and into lows, deflected by the Coriolis force into clockwise / anticlockwise spirals. This is the gradient wind that frames everything else — the background flow that other winds either ride on, fight, or hide under.

The famous example are the trade winds: a band of easterly flow circling the planet between roughly 30°N and 30°S, pushed by the temperature contrast between the tropics and the subtropical highs. Steady 15–25 kt, weeks at a time, almost the same direction every day. Riders chase them in spots like Dakhla, Tarifa, Cabarete, and across the Caribbean. The same belt is what carried sailing ships across the Atlantic.

In the mid-latitudes — Europe, North America, southern Australia — the gradient flow is messier: prevailing westerlies broken up by a parade of low-pressure systems and fronts moving from west to east. That’s where the rest of this list takes over.

Frontal winds

A front is the boundary between two air masses with different temperature, humidity, and density. Fronts move with the parent low-pressure system and bring the punchiest direction shifts a rider sees.

Warm front (warm air sliding over cold) — wind backs (rotates anticlockwise in the Northern Hemisphere) and freshens, often with rain ahead of it.
Cold front (cold air shoving warm air up) — sharp wind shift, usually clockwise (a veer), gusts spike for a few hours, then pressure rises and the sky clears.
Squall line — a row of thunderstorms along or ahead of a cold front. Wind can jump from 12 kt to 35 kt in a minute, then collapse just as fast. Get off the water.

A clean post-frontal afternoon — cold, dry air, steady NW or W flow at 15–25 kt — is some of the most reliable autumn riding in temperate latitudes. The trade-off is gust factor: post-frontal westerlies usually run 1.3–1.4 (see Kite Size from Forecast for what that does to your sizing).

Thermal winds

Wind driven by uneven heating, on a daily cycle — the thermal wind family. The mechanism is simple: the sun heats different surfaces at different rates (land vs water, valley floor vs ridge), warm air rises, cooler air rushes in to replace it. The breeze tracks the sun and dies with it.

The most ridable example is the sea breeze — onshore by mid-morning, peaking 15–25 kt by mid-afternoon, dying at sunset. It works at almost every coastal spot in spring and summer. The land/sea pattern has a sibling at every lake big enough to matter (Garda, Erie), a downsized cousin in the early-morning land breeze, and a vertical version in mountains:

Anabatic wind — sun warms a slope, air climbs it. Light upslope wind by mid-morning.
Mountain–valley breeze — cool air drains down the valley overnight, warm air rises up it by day. Garda’s Pelèr (morning northerly) and Ora (afternoon southerly) are the textbook pair.

Thermal winds are predictable but high-resolution: global models like GFS often miss them, while regional models like ICON and AROME resolve them. The full mechanism — and why it matters for your forecast — lives in Sea Breeze 101.

Gravity-driven (katabatic) winds

Cold air is dense. If you let it sit on a high plateau or glacier long enough, it eventually pours downhill under its own weight. That’s a katabatic wind — gravity-driven, often cold and dry, sometimes ferocious.

The textbook case is the Bora of the eastern Adriatic: cold continental air pools over the Dinaric Alps, then crashes down to the coast at 30–60 kt in winter, gusting well over 80. The Antarctic coast has the most consistent katabatic flows on Earth, blowing offshore for thousands of kilometres.

For riders, katabatic winds matter because they’re often offshore, very gusty, and underforecast by global models that smooth the terrain. They show up at fjord exits, at the foot of cliffs, and at the mouth of any valley pointing the right way at the right time of year.

Terrain-shaped winds

Mountains don’t just block wind — they reshape it. Three patterns repeat all over the world:

Föhn / Chinook — air forced over a ridge dries on the way up, warms as it compresses on the way down, and arrives on the lee side dry and warm. Föhn in the Alps, Chinook in the Rockies, Zonda in Argentina, Halny in the Tatras. Strong, gusty, and famous for melting snow in winter.
Gap and channel winds — flow squeezed through a narrow strait or valley accelerates (the venturi effect). The Mistral funnels down the Rhône valley at 30–50 kt; the Tramontane does the same down the corridor between the Pyrenees and the Massif Central. Tarifa’s Levante and Poniente both accelerate through the Strait of Gibraltar.
Lee waves and rotors — air pouring over a ridge oscillates downwind. Glorious from a glider, nasty for a kite if you’re parked under a rotor.

These winds are stronger and more directional than the gradient flow alone would predict. A 20 kt synoptic westerly can become a 40 kt Mistral by the time it reaches the sea.

Convective winds

Wind from a thunderstorm. A storm sucks warm humid air upward into the cloud, and a column of cold rain-cooled air falls back to the surface and spreads out as a gust front — a ring of wind racing outward at 30–50 kt for a few minutes.

Convective gusts are short-lived but dangerous: they can shift direction by 90° or more in seconds and lift a kite without warning. If a storm cell is anywhere within 15 km, the safe call is off the water until it passes.

Quick reference

Type	Driver	Time scale	Typical speed	Example
Gradient / trade	Pressure systems	Days–weeks	10–25 kt	Caribbean trades
Frontal	Air-mass boundary	Hours	15–35 kt + squalls	Atlantic cold front
Sea / lake breeze	Daily heating	6–10 hours	12–22 kt	Hyères, Garda
Katabatic	Cold-air drainage	Hours–days	30–60 kt	Bora
Föhn / Chinook	Lee-side compression	Hours–days	25–50 kt	Alps Föhn
Gap / channel	Venturi acceleration	Days	25–50 kt	Mistral, Levante
Convective gust	Thunderstorm outflow	Minutes	30–50 kt	Summer squall

Most days are a mix: a gradient westerly with a sea-breeze pulse on top, or a Mistral with thermal reinforcement in the afternoon. Reading the forecast is partly figuring out which mechanism is doing the heavy lifting.

Going deeper

This guide is the map. We’re working on a series of deep dives — one wind per post — covering the named local versions, forecast quirks, the best spots to ride them, and the failure modes to watch for. Mistral, Bora, Tramontane, Meltemi, Levante, trade winds, Föhn — each will get its own post in the coming weeks. The sea breeze already has its own.

Frequently Asked Questions

What’s the difference between a sea breeze and a thermal wind?

A sea breeze is a thermal wind — driven by uneven heating. “Thermal wind” is the umbrella term and includes sea breezes, lake breezes, mountain–valley breezes, and anabatic upslope flow. All run on the daily heating cycle and die at night.

Are trade winds and prevailing westerlies the same thing?

No. Trade winds are tropical easterlies between roughly 30°N and 30°S. Prevailing westerlies blow in the mid-latitudes (roughly 30°–60° in both hemispheres) and are much more variable, broken up by passing fronts and lows.

Why is offshore wind sometimes so gusty?

Often because it’s funnelling off terrain — over a cliff, through a gap, or down a valley. Smooth offshore flow over flat land is the exception, not the rule. Offshore wind that originates as katabatic drainage or Föhn descent is the gustiest of all.

What is a wind shear?

Two air masses moving in different directions or at different speeds, stacked or sitting next to each other. Frontal passages produce horizontal shear; thunderstorm gust fronts produce vertical shear. Both are kite-flipping conditions if you’re caught in them.

Which wind types do global models miss?

Anything with a length scale under ~25 km: sea breezes, katabatic flows, gap winds, valley breezes, convective gusts. Global models like GFS smooth those into nothing. High-resolution regional models like ICON and AROME resolve them — see GFS vs ICON for the why.

How Wavind helps

Most apps show one number from one model and call it the forecast. Wavind shows GFS, ICON, and AROME side by side. When you can see all three, the type of wind starts to leak out of the data: tight agreement on a steady number reads as a gradient or trade-wind day; the mesoscale models pulling above GFS in the afternoon reads as a sea-breeze ramp; one model spiking by 15 kt over the others points at terrain-driven channelling the others smooth away.

We turn that into a per-spot multi-model spread and a session score that bakes the disagreement in. Wide spread is itself information — the atmosphere is in a regime where small differences matter, and the wind type may not behave to script. On those days, ride conservative and let the forecast talk to you.