The Big Picture
Weather is a constant challenge in flying. Despite incredible advancements in technology, pilots are still significantly limited by mother nature. Understanding weather means pilots can anticipate and avoid unsafe situations. It also helps them avoid turbulence, find tailwinds, and get the most out of the airplane.
Lesson Notes
First, a correction: We drew the low pressure backwards. Low pressure air moves counter-clockwise and in. The diagram on the Weather Overview handout demonstrates this correctly.
Uneven Heating
Weather is the result of global uneven heating. Uneven heating causes air circulation, causing air to ascend (lows), descend (highs) and move sideways.
Coriolis Force
The Coriolis force causes winds to gradually turn to the right, in the Northern Hemisphere. As a result, airflow in the area between 30 and 60 degrees North is bent towards the right. This is the main reason why most weather systems in the U.S. and especially those on the West Coast come from the West.
Terrain
Terrain contributes to weather as well. Oceans provide moisture to the air and moderate coastal temperatures. Mountains cause air to rise, form clouds and create rain and snow. This often results in deserts on the leeward side of mountain ranges (e.g. Death Valley, Reno). In other areas of the country, wind patterns bring cold polar air south, creating cold winters (e.g. The Midwest).
Forecasts
Weather forecasts have become far more accurate in the last thirty years. However, weather is highly dynamic, and forecasts often fall short. As pilots, we must be aware of the current and forecast weather conditions and have a gameplan in case the weather changes.
Additional Resources
Flashcard Questions
What is ultimately responsible for earth’s weather?
How does warm air circulate?
How does cool air circulate?
Why does much of the weather in North America come from the west?
What is the Coriolis effect?
Weather on the west coast of the U.S. usually comes from the West, while weather in Hawaii often comes from the East. Why is this?
There is a small mass of air with a temperature of -25°C while the surrounding air is -45°C. Describe this situation referencing pressure instead of temperature.