Modern-day meteorologists rely on a vast network of advanced technologies to predict the weather, but that wasn’t always the case. Before satellites, computer modeling, and radar systems, people made forecasts largely by observing their surroundings.
The techniques and tools they used are still effective and accessible today. In fact, they’re perfect for anyone interested in becoming a backyard meteorologist. With a few handy instruments and a solid understanding of some basic weather concepts, you’ll be making your own forecasts in no time.
Gizmodo turned to two experts in meteorology and amateur forecasting for advice on how to get started. John Huth, a Donner Professor of Science at Harvard University’s physics department, teaches a class on backyard meteorology and the science of weather. Steve Seman, an associate teaching professor at Penn State’s College of Earth and Mineral Sciences, also instructs students in meteorology.
They broke down the basics, highlighted helpful tools, and offered words of wisdom for anyone looking to learn more about the weather in their neighborhood.
Step 1: Learn the fundamental science
Weather is driven by six key variables: temperature, atmospheric pressure, cloud formation, wind, humidity, and precipitation. Changes in these variables—and interactions between them—create different scenarios and patterns. Once you understand that, you can begin thinking about how air moves around in the atmosphere.
“We usually start thinking horizontally, at the surface of the Earth, and then go into vertical [movement],” Seman said. Horizontal air movement—or wind—drives vertical air movement through convergence and divergence. Convergence is the inflow of air to a given area, causing it to pile up and rise. Divergence is the outflow of air from a given area, causing it to spread out and sink.
“Those horizontal air movements are also related to vertical air movements,” Seman explained. The first thing to understand is that both atmospheric temperature and pressure decrease with elevation. “These two [gradients] are givens associated with the way the Earth’s atmosphere operates,” Huth said.
As warm air rises, it encounters lower pressure and expands, then cools in a process called adiabatic cooling. If it cools past the dew point, moisture condenses around tiny airborne particles, forming clouds and sometimes storms. When air sinks, skies clear.
These are some of the most basic concepts in atmospheric science. While there’s much more to learn, mastering the fundamentals provides a solid foundation for understanding Earth’s complex weather system.
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