FOCUS: A snowflake’s life is one of constant change, from its trip through the sky to its resting place in the snow bank. Each one is a unique, six-sided crystal with temperature and humidity as key factors determining their shape, size, and design.
INTRODUCTION
Objective: To begin to explore and ask questions about snowflakes.
If it’s snowing, provide children with black felt squares and magnifying lenses to catch and observe snowflakes. If not, put out several snowflake photographs, and ask children what they notice about them. After they mention some similarities and differences, ask them to sort them.
Materials: squares of black felt or dark fabric, chilled in freezer or outdoors; magnifying lenses; optional: Snowflake Photo Set: photos of various snow crystal categories
SNOW CRYSTAL CATEGORIES
Objective: To observe snow crystal photos and sort into categories based on their design features.
Using the Types of Snow Crystals diagram, review the various design features and growth patterns of different snow crystals. Point out that as each type of snowflake grew, decorative patterns were repeated on all six sides, creating symmetrical designs. In small groups, have children sort snow crystal photos into these categories based on their design.
Alternatively, give each child a photo and have them sort themselves into snow crystal type.
Materials: Snowflake Photo Set: photos of various snow crystal categories, Types of Snow Crystals diagram.
UPPER GRADES CHALLENGE: Snowflake Predictions (Grades 5-6)
Objective: To use temperature and humidity data to make predictions of possible snow crystal type.
Have students work in pairs to interpret and discuss the Snow Morphology Chart. In particular, have them note the temperature range at which different types of snow crystals form and note how their shapes are affected by moisture level (i.e. simpler when moisture levels are low and more complex at higher humidity). Provide different temperature and humidity scenarios, such as those in the table below, and have students predict the type of snow crystal that might form (e.g. if the temperature in the cloud is 5°F and the humidity is 0.1, what kind of flakes are likely to form?) Have each group come up with a set of conditions and ask others to determine what type of crystal is likely to form.
Materials: Snow Morphology Chart for each pair of children.
PUPPET SHOW “No Two Alike?”
Objective: To learn the conditions necessary for different snow crystal formation and compare the designs of five different snow crystals.
Perform the puppet show, or have a group of children perform it for the class. Afterward, ask questions to review the key details and vocabulary in the story. How does a snow crystal begin? What conditions are necessary to form each of the five types of snow crystals introduced in the puppet show?
Materials: puppets, script, stage.
PAPER SNOWFLAKES
Objective: To create six-sided snowflake models.
Following the Paper Snowflakes directions, children will fold and cut paper to create their own one-of-a-kind snowflakes. For younger children, follow directions using coffee filters, as they are easier to cut. Older children will make snowflakes from squares of paper.
Once folded, point out that each cut made will be repeated six times around the snowflake, creating a repeating or symmetrical pattern on the finished snowflakes, similar to those seen in real snowflakes.
Materials: round coffee filters or square sheets of paper, scissors, Paper Snowflakes directions.
SNOWFLAKE DANCE (Grades K-2)
Objective: To act out the formation of six-sided snowflakes.
Explain that children will be acting out how snowflakes form. Review the key ideas presented in the puppet show by asking children what is in the center of every snowflake and how many sides or arms they usually have. Depending on the class size, choose two or three children to be snow seeds. Select six children to hold hands and form a circle around each snow seed. Have an adult work with or, depending on numbers, join each snowflake. Each adult will direct the children in their “snowflake” to make different arm motions, creating different snowflake shapes. The snow seed can change its arm position too or move around in the center of the flake. Optional: play music (Tchaikovsky’s Waltz of the Snowflakes) and have the children slowly sway and move their arms pretending their snowflake is changing as it falls gently from the sky.
Materials: optional: music recording such as Tchaikovsky’s Waltz of the Snowflakes..
WINTER WEATHER SKITS (Grade 3-6)
Objective: To model the processes that lead to the formation of three types of frozen winter precipitation: sleet, freezing rain, and graupel.
Review the formation of snowflakes using the Snowflake Guided Imagery script. Afterward, have the children work in small groups. Provide role cards and props plus a skit description and diagram that explain how their particular type of winter precipitation forms. Using the cards and props, the children will model how their type of winter precipitation forms and its possible effects on the natural world and/or people’s reactions to it. The other children will try to guess what type of precipitation is being presented.
Winter Weather Skit Descriptions
The words in bold can be made into cards for the students to wear to help identify their role in the skit.
Freezing Rain
Freezing rain is rain that falls when temperatures near the ground are below freezing. Rain drops form in layers of warmer air higher up in the atmosphere. As they fall, they pass through a layer of below freezing air (32°F or colder) near the ground. But rather than freezing into ice, they remain liquid. When they come in contact with objects at the surface they freeze instantly on contact coating everything in a layer of ice or glaze. When there’s a significant accumulation of this glaze, we call it an ice storm. The weight of this ice can bring down power line, snap trees, and form “black ice” on roads and icing on the wings of airplanes.
Sleet (also called Ice Pellets)
Sleet is precipitation composed of frozen raindrops. It often forms when snowflakes pass though a layer of warm air where they melt into raindrops. When the rain passes back through a layer of air with below-freezing temperatures (32°F and colder), the raindrops freeze into transparent pellets of ice which often bounce when they hit the ground. Sleet stings when it hits your face, and accumulated sleet on roadways can be very slick.
Graupel (also called Tapioca Snow or Snow Pellets)
Graupel is a form of frozen precipitation consisting of snow crystals and supercooled water droplets frozen together. Falling snow crystals pass through a layer of liquid cloud droplets, which freeze onto their surface. This freezing of droplets onto the crystal (called accretion) continues until the original snow crystal is coated, making it almost indistinguishable. Graupel appears opaque white, is lightweight due to small air bubbles throughout its structure, and easily breaks apart.
(Note: Hail tends to be a warmer weather phenomenon.)
Materials: Snowflake Guided Imagery script, Winter Weather Skit descriptions, Winter Weather diagrams and role cards for sleet, freezing rain, and graupel. Optional props might include: clear plastic sheet for ice glaze, balls of crumpled plastic wrap or tin foil for sleet, cotton balls for graupel.
COLLECTING CRYSTALS
Objective: To collect, identify, and observe the intricate designs of real snowflakes.
Beforehand, chill felt or fabric squares. When it is snowing, hand out the chilled fabric squares and have children use these to collect falling snowflakes. With magnifying lenses, have them view their snow crystals up close and compare them to the snow crystals depicted on the Types of Snow Crystals diagram.
Materials: squares of black felt or dark fabric, chilled in freezer or outdoors; magnifying lenses, Types of Snow Crystals diagram.
SNOW SCOUTING
Objective: To make observations about snow around the schoolyard.
Have the children collect, measure and observe snow in different ways. Provide each small group with two clear plastic cups in which to collect snow, and bring along rulers or measuring tapes, magnifying lenses, and snow shovels. In small groups with an adult, do the activities on the snow scouting card.
Snow Scouting
Collect samples of snow in two containers: one loosely scooped, the other tightly packed. Make predictions about how much water each will contain when melted. Use markers to indicate predicted water lines. Afterward, bring the snow-filled cups inside to melt. How does the volume of water compare to their predictions? To the volume of snow?
Using rulers, measure depth of snow at different places in the schoolyard. Can children think of reasons to explain why it might be deeper in one place than another?
Look closely at snow on ground. Can you still see different snow crystal types, or have they changed? And how?
Using snow shovels, dig down through the snow to see if you can find different layers. What do you think the layers represent? Is the surface snow soft or crust-like?
It’s fun to collect big pieces of crust to use in the Snow Sculpture activity.
Materials: Snow Scouting card, small containers, two per group; markers, rulers or measuring tapes, magnifying lenses, snow shovels.
SNOW SCULPTURE
Objective: To create symmetrical art assemblages outdoors using snow and other natural materials.
Show the children examples of environmental artwork created in winter by artists such as Andy Goldsworthy, Simon Beck, and Vermont artist Sally J. Smith. Using snow and other natural materials, have children work together in small groups to create environmental art assemblages that feature six-sided symmetrical designs. Take a tour of the finished artwork and photograph each piece. If possible, leave the artwork in place for others to enjoy.
Materials: winter environmental art examples, camera to photograph artwork.
JOURNAL ACTIVITY AND CLOSING THOUGHTS
Objective: To record observations about snowflakes and how they form.
Provide Hexagon Templates for the children to use to create their one-of-a-kind snowflake. Faint lines drawn in between the opposite points of the hexagon divide it into six sections. Explain that to make their snowflake symmetrical, anything they draw in one of the six sections, either inside or outside, must be repeated in the remaining five. Afterwards, in small groups, have children share their snowflakes and one thing they learned about snow.
Materials: Hexagonal template, one per child; drawing materials.
Nearby Nature 