How to read wind barbs — wind speed and direction symbols

Wind barbs are symbols for indicating wind speed and wind direction on weather maps. In this article, you'll learn more about what it is, how to read wind barbs, and where to get a wind forecast with such a symbols.

What are the wind barbs?

Wind barbs are symbols on the map that show wind direction and speed at some specified location. It is a familiar format for displaying the wind to all meteorogists, yachtmen, and others. That's how it were drawn on the synoptic maps before, and so many people are used to seeing it. Now you can see wind barbs on digital maps, too.

An example of a wind barb used in the Windy.app. Valerya Milovanova / Windy.app

How to read wind barbs?

Reading wind barbs is simple and complicated at the same time, much like the multiplication table. Simple — because they are essentially simple signs that are formed by a single formula. Difficult — because you have to learn it, which takes some time. So here it is:

First, the barb has three parts: a long line, an extra lines on the long line (called "feathers") and/or triangles also called "flags", and most often a dot.
Second, the speed of the wind is correlates with the number of extra lines. The long extra line (long feather) is 10 knots (kts), short extra line (short feather) is 5 kts. A triangle is 50 kts.
Third, the circle with no lines (and no extra lines and/or flags) instead of a dot simply mean no wind. It is used when winds are 2 kts (mph) or less.
Forth, the wind direction is the position of the line in 360 degrees. In other words, the wind blows from the extra lines and/or flags to the opposite direction — often dots.

How to read wind barbs. Illustration: Valerya Milovanova / Windy.app

The standard wide set of weather barbs includes symbols to indicate wind from 0 knots to 120 knots with a 5 knots step. But most likely you will only need the first dozen barbs for wind up to 30 meters per second. Stronger winds are considered hurricane winds and do not occur often.

How to read wind barbs. Illustration: Valerya Milovanova / Windy.app

In the Windy.app wind barbs are located in the nodes of the weather model grid — points on the map where the weather is predicted. This excludes interpolation (forecast errors) — the forecast is as accurate as possible. In this implementation, it is a unique feature of the Windy.app you will not find in other weather mobile applications. The wind barbs source is one of the 10 weather models used in the app. It's updated every three hours.