This week we are learning about the four main types of precipitation. They are rain, snow, sleet and hail. Most of us are familiar with each of these types of precipitation but do you know how each type forms in the atmosphere? First graders do! We started our learning by watching a meteorologist explain rain, snow and sleet. First graders already know that precipitation happens when water molecules in a cloud stick together until they form a droplet that is heavy enough to fall to earth. Rain forms when this happens in a warm cloud and all of the air in the the atmosphere below is above freezing temperature. Snow forms in a similar way, but with a cloud and atmospheric air that are both below freezing.
Next, we watched a different meteorologist explain the distinction between hail and sleet. When they land on our sidewalks or cars, both of these types of precipitation look similar, but they form in different ways and different seasons.
Sleet is formed in a “warm air sandwich” when a frozen cloud drops snow into a layer of warm air. The snow melts into raindrops and then freezes again when it hits a layer of very cold air near the surface of the Earth. This happens only in winter months, when the air near the surface of Earth is cold.
Hail forms in the summer months when water molecules are moved up and down in the atmosphere from a frozen cloud to warm air over and over again. This process turns snowflakes from the cloud into ice balls and new layers are added to the ice ball each time it moves back and forth from warm to cold.
First graders helped Ms. Ursino make a big diagram of the formation of each of these types of precipitation on the dry erase board using a red marker to represent warm air or clouds and a blue marker to represent cold air or clouds. Then students each created their own diagram independently.