WHAT IS WEATHER? Weather tells us what the outside air is like. There are Why did the woman go outside with her purse open? She thought there was going to be some change in the weather! many kinds of weather, such as hot, cold, sunny, rainy, snowy, and windy. Storms and winds can change the weather in a hurry. WEATHER PATTERNS CAN BE OBSERVED Did you know weather follows patterns? Every place on Earth has a weather pattern. A weather pattern is what the weather is usually like in a 1 Some deserts have a hot, dry weather certain place. There are many kinds of weather patterns, or climates, all over the world. In some locations or places, the weather pattern is hot and dry, such as a desert. Some climates are cold and windy, like the Arctic. Many plants and animals can only live in one climate. For example, animals living in a hot
rainforest would not survive in the cold South Pole. Why do polar bears and poison dart frogs need to live in different climates? What kind of weather do you like best? Do you look forward to playing in the snow? Or do you wait all year for the hot days of summer? Polar bears and poison dart frogs live in different climates. Weather patterns in some locations have both cold and warm weather. The weather pattern changes with the season. Seasonal changes bring cooler weather in the winter. Summer means warmer weather. Both people and animals use weather patterns. Families plant gardens in the spring when there is plenty of rain. Some people go on vacation every summer when the weather is warmer. Others enjoy the snow, so they vacation in the 2 People use seasonal changes to plan activities. winter. Some animals such as squirrels store food in the fall. They know food will be hard to
find in the winter. Monarch butterflies migrate to a warmer climate before winter comes. April showers bring May flowers! People have been watching or observing weather patterns for thousands of years. They would watch the sky to Low, dark clouds tell us a storm is coming. see what the weather would be like. Was the sky clear or cloudy? What kinds of clouds were in the sky? Would the clouds bring rain or snow? People still observe the weather patterns today. Read about what some 4 th grade students saw one day when observing the weather: It was 12:15 PM on August 11, 1999. Fourth grade students at Rosamond Elementary School in West Jordan, Utah went outside to observe the weather for their school's web site. Today's report would be different. The air was warm and very windy. Something very strange was about to happen. 3
Looking to the west, the students saw dark clouds over Herriman, Utah. They took two pictures of the dark clouds. The students went back to class. They entered their information into the computer. An hour later, the students were shocked to hear that a thunderstorm and a tornado had struck downtown Salt Lake City. The tornado caused much damage. The students realized the storm had begun over Herriman at about 12:00 PM. Their pictures showed the beginning of the thunderstorm that formed the tornado. Source: USOE 4 th Grade Weather Teacher Resource Book Tornados are called twisters. Dark storm clouds are part of Utah s seasonal weather pattern, but rarely do they signal a tornado! The students at Rosamond Elementary had a very unusual experience while observing the weather. Have you ever seen the shape of an animal in the clouds? Watching clouds can be fun. But observing clouds can also help us interpret or 4
understand the weather. Three kinds of clouds are stratus, cirrus, and cumulus clouds. Each cloud brings its own type of weather. Stratus Clouds Cirrus Clouds Cumulus Clouds Stratus clouds are layered and stretch across the sky. They are low, dark gray clouds. Plan for rain or snow if you see stratus clouds. Cirrus clouds are thin, wispy, and high in the sky. You may see cirrus clouds on sunny days. They signal a change in the weather. Cumulus clouds are big, puffy, and white. Cumulus clouds can be seen in fair weather. If cumulous clouds bunch together and turn dark, a thunderstorm could be on its way. When outside, observe the clouds. What kind do you see? What s you weather prediction? 5
WEATHER PATTERNS CAN BE DESCRIBED How would you describe today s weather? Is it hot or cold, snowy or sunny? Is there any precipitation (snow, rain, hail, or sleet) falling? Meteorologists are scientists who study or analyze weather and weather patterns. They are weather watchers. A meteorologist studies the weather. Meteorologists collect data or information about the weather and record it on the computer. Then they use words such as rainy, windy, hot, cool, cold, snowy, sunny, dry, cloudy, clear, stormy, foggy, sunny, and breezy to describe the weather. For example, think of the weather patterns we see in Utah during the winter. Meteorologists usually describe winter as cold, snowy, and windy. Or perhaps winter could be described as foggy and stormy. A summer day may be hot, clear, and sunny. 6
But seasonal weather can have variations or differences, too. Has something like this ever happened to you? Imagine leaving for a picnic on a sunny summer day. After playing at the park, it s time to eat. Just as you begin your picnic, you see dark clouds everywhere. Soon heavy rain begins to fall. All of a sudden, you wish you had a jacket and your umbrella! What started out as a clear, sunny day Weather variations can surprise us! quickly changed to a stormy, rainy day. Variations can create surprises in the weather! WEATHER PATTERNS CAN BE MEASURED How is a ruler like a scale? They are both tools used to measure things. People also use tools for measuring weather patterns. A thermometer is a tool which measures the temperature of the air. A weather vane measures the direction the wind is blowing. A rain gauge measures how much rain has fallen. This thermometer shows temperature in degrees Celsius and Fahrenheit. 7
Weather watchers can make decisions or conclusions about the weather by measuring with these tools. Let s take a look at each of these tools. Thermometers measure temperature by degrees to show how hot or cold the air is outside. Two types of thermometers may be used. One kind of thermometer is a metric thermometer. It measures the temperature in degrees Celsius. Another kind of thermometer measures the temperature in degrees Fahrenheit. By analyzing the temperature outside, meteorologists can help people understand the weather pattern. People will be able to plan for cold or warm weather. A weather vane shows which direction the wind is blowing. It points North, South, East or West, depending on the direction from which the wind is coming. People put weather vanes on their homes, barns, or garages. A weather vane shows wind direction. 8
There is another way to know the wind direction. Stand facing the wind. If you are facing east and the wind is blowing in your face, the wind is an east wind. The direction of the wind can tell us what kind of storm to expect. Rain gauges measure how much rain falls. You can make a rain gauge by taping a ruler to a wide-mouth jar. Set the bottle outside before a storm. When the rain stops, use the ruler to see how many inches of rain fell. 9 What did one lightning bolt say to the other! You re shocking! A rain gauge measures rainfall. There are many ways to learn about the weather. We can all be weather watchers! Observing, describing and measuring weather patterns are interesting and important. Knowing what weather to expect will help us plan each day s activities. Studying seasonal weather patterns will help us plan for future events. We will know when to plant a garden, take a vacation, plan a party, or prepare for a storm. Then we won t be shocked if there s some change in the weather!
GLOSSARY analyze: to study cirrus: thin, feathery clouds climate: the weather pattern conclusions: decisions made after studying data cumulus: puffy, white clouds data: facts or items of information interpret: to explain or give the meaning location: an area or place meteorologists: scientists who study the weather observe: to watch or inspect precipitation: hail, rain, sleet, snow rain gauge: a tool to measure rainfall seasonal: happening during a certain season of the year stratus: low, layered, gray clouds 10
temperature: the measurement of hotness and coldness thermometer: a tool to measure temperature variations: changes or differences from what is usual weather: what the outside air is like weather pattern: the climate, what weather is usually like in a certain area or location weather vane: a tool to measure wind direction 11