Water Cycle - Weather (K)
Pre Lab 

   
OBJECTIVES:
  • Comparing different types of weather.
  • Exploring rain, snow, and sun.
VOCABULARY:
  • rain
  • snow
  • sun
  • weather
MATERIALS:
  • worksheet
  • crayons

Students use a worksheet to describe different types of weather.

BACKGROUND:

Weather is a phenomenon that children have experienced. They learn early to look outside before they dress to play outdoors. Television helps children "see" other types of weather around the world. So even though they donít experience it, they are familiar with the word. Some children have never seen snow, lightning, or a tornado. However, stories about severe storms have always entertained children.

Thunderstorms are generated by temperature imbalances in the atmosphere. The warming of the air near the Earth's surface and/or the cooling of the air above the surface causes instabilities and convective overturning of various layers of hot and cold air.

Lightning is an effect of electrification within a thunderstorm. As the thunderstorm develops, interactions of charged particles produce an intense electrical field within a cloud. A large positive charge is usually concentrated in the frozen upper layers of the cloud, and a large negative change, along with a smaller positive area, is found in the lower portions. Thunder is the sound produced by the explosive expansion of air heated by a lightning stroke. When lightning is close, the thunder sounds like a sharp crack and more distant strokes produce growling and rumbling noises. Because the speed of light is much greater than that of sound, we see a lightning bolt before we hear the thunder.

A severe thunderstorm may spawn a tornado, a violently rotating column of air which descends from a thunderstorm cloud system. On the average, tornadoes move about 30 miles an hour, however, some move very slowly while others speed along at 60 miles an hour or more.

Floods are a natural and inevitable part of life along the rivers of our country. Some floods occur seasonally when winter or spring rains, coupled with melting snows, or torrential rains associated with tropical storms, drain. Other floods are sudden, resulting from heavy localized rainfall. These flash floods are raging torrents which rip through river beds, urban streets, coastal sections and mountain canyons after heavy rains, and sweep everything before them.

Hurricanes are storms that start over tropical waters. The blazing Sun beats down on the ocean waters day after day and the air above this water gets hot. As cold air moves in, it pushes the hot air straight up until the hot air reaches a cool layer of air. The water vapor condenses very suddenly and becomes a driving rain. Cooler air from the outside moves in, in a whirling motion, like water going down a drain. The center or "eye" of the hurricane is calm, but all around it the winds and rain are swirling.

PROCEDURE:
  1. This introductory coloring exercise has the students looking at rain, snow, and sun dominated weather. Before the students color, direct their attention to some of the characteristics of that specific type of weather.
      
  2. You might also want to go over some other weather types. Below is a list that can help guide your discussion.
      
    Rain: Comes from clouds; wet liquid; different types of clouds produce different intensities of rain.
      
    Snow: Comes from cold clouds; solid water; always has a hexagonal shape (an ice crystal grows in this pattern).
      
    Sun: Clear day; depending on where the sun is in the sky controls how hot it is.
      
    Hail: Frozen rain (not a crystal like snow).
      
    Hurricane: High winds, lots of rain.
      
    Tornado: High winds that swirl around violently.

[Dictionary] 
  [Back to Water Cycle Grid]  [Back to Weather (K)]