The Weather Notebook: Map

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When you stop to think about it, the idea of translating the complexities of physical reality into a two-dimension map is pretty strange, especially given the limited tool kits of the original mapmakers. But think what a leap of imagination it took to map something as fluid and ephemeral as weather. No wonder it didn't happen until the Scientific Revolution.

Hi, I'm Bryan Yeaton and this is the Weather Notebook.

The germ of the idea goes back to English astronomer Edmond Halley, who published a very elegant map of the trade winds and monsoons in 1686. Over a century later, German physics professor Heinrich Wilhelm Brandes took the weather map a giant step forward with two key innovations - plotting lines of equal air pressure, known as isobars, and indicating wind and air pressure on the same map. In 1819, Brandes completed the Herculean task of mapping Europe's weather for every day of 1783 - 365 maps in all.

An American mathematics professor by the name of Elias Loomis further refined the weather map in the early 1840s by adding temperature, sky conditions and precipitation. The Loomis map became known as the synoptic weather map because all the elements of weather could be seen together at a glance - a kind of visual synopsis of weather. The icing on the cake came in the early 20th century, when a team of meteorologists in Bergen, Norway, devised the now familiar saw-teeth notation for weather fronts - sharp triangular barbs representing cold fronts, soft semi-circles for warm fronts, and alternating barbs and semi-circles for occluded fronts.

Over two centuries in the making, the weather map was clearly a great idea. Just try to imagine forecasting without it.

The Weather Notebook is a production of the Mount Washington Observatory, supported by Subaru, the beauty of all wheel drive. Thanks today to David Laskin of Seattle Washington. For more on weather maps, visit our website at weathernotebook.org