Observing the Weather
by Stacie Hanes How hot was it today? How cold was it last night? How much rain or snow fell yesterday? Was it cloudy, windy or foggy? To know the answers to these questions, someone had to observe the weather. Some weather observations (like how cloudy it is) can be made with your eyes and some observations can be based on how it feels (like temperature or wind), but the best way to observe the weather is to take measurements. Several types of instruments can help. A thermometer tells us how warm or cold it is, a rain gauge tells us how much rain fell and a ruler can be used to measure snow. Anyone can make observations of the weather. In fact, you might want to keep a daily log of the temperature, what the sky looked like and whether there was any precipitation. Although the National Weather Service uses a variety of instruments to observe the weather, we also rely on observations taken by volunteers across the country. Your family or school can contribute to the weather information collected around the country by joining a volunteer network of weather observers. One such program is the Community Collaborative Rain, Hail and Snow Network, or CoCoRaHS for short. CoCoRAHS weather observers work together to measure and map precipitation in their local communities and across the country. So how does it work? Every time it rains, snows or hails, volunteers make precipitation measurements and enter them onto a website. Once the information is entered, it can be displayed on a map. The observations can then be used for many situations, like helping the National Weather Service decide whether to issue flood warnings. Measuring rain and snow is easy. To measure rainfall, you will need a rain gauge. Be sure to place it outside on level ground, and away from trees and buildings. After it rains, simply read how much rain fell into the rain gauge and record your observation. Snow can be measured with a ruler or, for the real big storms, with a yardstick. Your snowfall measurement will be better if you use a “snowboard.” A snowboard is simply a board that is painted white. Before a storm, place your snowboard well away from trees and roofs, and make sure to mark where you put it so you can find it when it is covered in snow. You should try to measure the snow as soon as the storm ends to get an accurate measurement. If you wait too long, the snow may melt, settle, blow away, drift or evaporate. If it’s been windy, you may need to take several measurements in the area and average them in order to get an accurate measurement. If you are interested, the CoCoRaHS network is always looking for more volunteer observers. If your family or school would like to become a volunteer weather observer, simply visit the CoCoRaHS website (www.cocorahs.org) and click “Join CoCoRaHs.” Additional details on how to observe and report rain and snow are available on the website. Stacie Hanes is a meteorologist with the National Weather Service in Gray, Maine.
