Adaptation and Behavior

Weather

Lesson #7: Types of Precipitation

Time Frame: 60 minutes or 2 sessions of 45 minutes

Learning Standards: Science Earth and Space Science: Weather 1) Explain how air temperature, moisture, wind speed and direction, and precipitation make up the weather in a particular place and time. 2) Distinguish among the various forms of precipitation (rain, snow, sleet, and hail), making connections to the weather in a particular place and time. Skills of Inquiry  Ask questions and make predictions that can be tested.

Technology/Engineering Materials and Tools 1.1Identify materials used to accomplish a design task based on a specific property, i.e., weight, strength, hardness, and flexibility. 1.2Identify and explain the appropriate materials and tools (e.g., hammer, screwdriver, pliers, tape measure, screws, nails, and other mechanical fasteners) to construct a given prototype safely. Engineering Design 2.1 Identify a problem that reflects the need for shelter, storage, or convenience. 2.2 Describe different ways in which a problem can be represented, e.g., sketches, diagrams, graphic organizers, and lists. 2.3Identify relevant design features (e.g., size, shape, weight) for building a prototype of a solution to a given problem.

Student will be able to: 1) Describe precipitation and compare and contrast the different types of precipitation. 2) Design and create a device to measure precipitation.

Focus Activity: Ask the students to answer the following question in their science notebooks: What types of water fall out of the sky? Discuss the answers as a class and talk about how some types of precipitation are liquid (rain) and some are solid (snow, sleet, and hail).

Introduction: Review with students that weather occurs because of the interaction between the sun, atmosphere, and the earth. Explain that water in the atmosphere (from the water cycle) falls back to the earth as precipitation. Review with the students that evaporated water from the earth forms clouds that create precipitation.

Activities: 1) Discuss the different types of precipitation as a class. Ask students to share their experiences with these different types of precipitation. Use the pictures of the different types of precipitation provided. Rain develops when growing cloud droplets become too heavy to remain in the cloud and as a result, fall toward the surface as rain. Rain can also begin as ice crystals that come together to form large snowflakes. As the falling snow passes through the freezing level into warmer air, the flakes melt and collapse into rain drops. Hail is a large frozen raindrop produced by intense thunderstorms where snow and rain can coexist. As the snowflakes fall, liquid water freezes onto them forming ice pellets that will continue to grow as more and more droplets are accumulated. The hail stone reaches the ground as ice since it is not in the warm air below the thunderstorm long enough to melt before reaching the ground. Sleet is frozen raindrops that bounce when they hit the ground or hit something else. Sleet begins as snow high in the atmosphere and then partially melts in warmer layers of air and then refreezes in colder areas of air as it falls. Snow is ice crystals that form into flakes. Snow forms at temperatures below freezing. For snow to reach the earth's surface the temperature in the troposphere needs to be at or below freezing. It can be slightly above freezing in some layers if the layer is not warm or deep enough to melt the snow flakes too much. 2) Lead a class discussion about what types of precipitation are most common during different times of the year, making connections between types of precipitation and temperature. When does it snow in Williamstown? How does it feel outside when it is snowing? What about sleet? Hail? When does rain occur? Does it need to be cold for it to rain? How can you tell when a rainstorm might be coming? Does the air feel humid (damp and heavy)? 3) Divide the students up into four groups. Assign each group a type of precipitation (rain, hail, sleet, or snow). Give each group a piece of paper with the name of their precipitation and pictures (provided). Ask the groups to come up with a short skit that demonstrates the characteristics of their type of precipitation. Give the class a box with different clothes and other objects such as snow boots, hats, scarves, mittens, umbrellas, rain boots, etc. Each skit should do the following: a. Describe the type of precipitation b. Explain how people respond to the precipitation c. Explain some effects of this precipitation Work with the groups to develop their ideas and assist groups as necessary in coming up with a storyline and presenting all of the relevant information. 4) Give each group the opportunity to present their skit to the class. Discuss each type of precipitation after the skit and go over the similarities and differences between snow, sleet, rain, and hail. 5) Discuss how to measure precipitation. Review the data collected from the weather station over the past couple of weeks. Ask the students to design and make devices that can measure snow, rain, hail, or sleet. Provide the students with plastic and glass containers, paper, rulers, and other supplies as necessary. If time permits, allow students to explain their devices to the class and place them outside to make measurements.

Closure: Discuss the following questions as a class. Which type of precipitation is water in its liquid form? Which types of precipitation are made of water in its solid form? How is sleet different from hail? How is rain different from snow? How are rain, sleet, snow, and hail similar?

Assessment: Science notebook responses, participation in class activities and discussions, participation and creation of a precipitation skit, design and creation of a device to measure precipitation

Resources and Materials: Water cycle diagram, pictures of different precipitation, box with different clothes and other objects (not provided), glass and plastic containers, rulers (not provided), paper (not provided), tape