Teaching the Science of Weather
Many non-meteorologists, including otherwise well-informed adults, don’t realize that weather forecasting is a science.
Meteorologists who visit schools with the message, “If you want to become a weather professional, study all of the math and science you can,” are sometimes asked, “why do I need to study science to be a broadcast meteorologist?”
Their parents, like other adults, could well have the same question.
They obviously think that the right clothing is more important than understanding calculus for the only meteorologist they know about, the one on television.
In fact, for many people, their favorite broadcast meteorologist is probably the only scientist they could name, if they know the meteorologist is a scientist.
The AMS Weather Book: The Ultimate Guide to America’s Weather can help you explain not only why meteorology is a science, but how it can give you insights into the wider world of science. One of the themes running through the book is that the growth in our understanding of weather is a part of the story of how we have come to understand the physical world.
Material from the book and its accompanying Web site can help a teacher introduce science to students from elementary school to advanced placement physics in high school.
The sky as a school
The sky and weather are wonderful teaching resources because they are always available at no cost. An elementary school teacher could use the graphics and text in Chapter 1 to help students understand some everyday things such as why the sky is blue and clouds are white and different shades of gray.
Rainbows and other kinds of colors in the sky–the book explains and illustrates why many of them are not rainbows–can introduce science on many levels.
Elementary students are often told that Roy G. Biv, which is for the colors “red, orange, yellow, green, blue, indigo, and violet” from the top to the bottom of a primary rainbow, is a good way to remember the “colors of the rainbow.”
An elementary teacher could read the “It’s time to retire Roy G. Biv” sidebar on page 13 of the AMS Weather Book and then use an actual rainbow or photos a class sees to lead a discussion about the difference between observations of the world and what people say about the world.
A high school advanced placement physics teacher could refer the students to the reference to the book, The Rainbow Bridge, listed under sources for page 13 on the Chapter 1 sources page on the book’s supplemental Web site. The discussion and sources in this book could lead them into the basic physics of color and also the human perception of color.
Chapter 1 also explains on pages 15 and 16 why the sky is blue and briefly tells the story of how 19th century scientists worked out our current understanding.The book’s explanation of this will probably be enough for most readers. Those who want to know more, such as advanced placement students, can check out the source listed for Page 16 on the Chapter 1 sources Web page.
Most people are interested in weather forecasts, at least at times, such as when planning an outdoor wedding, when the weather is important to them. Helping them understand how predictions are made, and the limitations of predictions can help you teach a little about science.
Adults, who obviously don’t know the difference between science and folklore, ask about “forecasts” by woolly bear caterpillars.
Adults, and maybe children, misled by stories published by clueless newspaper or Web site editors often ask about almanac “forecasts.”
A teacher could use the information in the “Folklore and science” section on Page 7 of the AMS Weather Book to lead a discussion of how one would go about conducting a scientific study of woolly bear forecasts.
A class could do a months-long project on tracking the skill of almanac forecasts. Chapter 7 of the AMS Weather Book, which covers weather forecasting, explains forecasting skill in the section on “Simple forecasting” on Page 155. It describes how to use climatology–the average weather–and persistence–forecasting that tomorrow will be like today–as “no brain” forecasts as a skill standard.
In simple terms, skill refers to the ability to do a better job than a “no brains” forecast.
To check an almanac’s predictions, students could pick several cities in different parts of the nation to track for a month or even a season. A chart would be made with room for the almanac’s forecast, a climatology forecast, a persistence forecast, and the actual weather for each day of the month or season.
To keep it simple, the students could use forecasts and results for precipitation (rain and snow) only.
A student or team of students could be assigned to track each city. They would list the almanac forecast for each day for each location. Then they would make climatology forecasts by drawing results at random. They would begin by obtaining weather averages for each city.
If in November, for example, a city averages 10 days with precipitation, the students would write “wet” on 10 pieces of paper and “dry” on 20 pieces and mix up all 30 pieces in a box. If it snows on the average of three of the 10 wet days, they’d write “snow” on three pieces of paper and leave seven blank and put these in another box. They would then draw, without looking, a piece of paper for each day. If it says “wet” they’d draw from the other box. If it says “snow” they’d enter snow for that day, if it’s blank, they enter “rain.”
To obtain information on weather averages for locations in the United States, you can go to the National Climatic Data Center’s U.S. Climate Normals page and use the pull-down menu on the right side to select the state and then from the state list of weather stations pick the one you’re interested in.
An easy way to obtain the official weather observations for a city is to go to the National Weather Service’s Offices and Centers page and then click on the link to the city you are interested in.
On the page for the city’s NWS office look on the left side for “Climate” and click on “local” under this heading. Here you’ll see the cities that the office tracks. You want the “Daily climate report” for the city for the previous day, under “archives.”This information will be used as the actual weather for that day and the persistence “forecast” for the next day.
The more cities the students track the better. As explained on Page 155 of the AMS Weather Book climatology and persistence forecasts can sometimes be very “accurate,” especially for July precipitation for Los Angeles.