WELCOME, STORM CHASERS!
THE BIRTH OF A TORNADO
A thunderstorm is usually where a tornado is born. The storm begins as warm, humid air rises upward from the ground creating updrafts. These updrafts cool in the upper atmosphere. As they cool, the moisture in them forms clouds. The water droplets in the clouds grow larger as water vapor around them liquifies or condenses.
When these water droplets then begin to fall, downdrafts are created. The downdrafts collide with the newly formed updrafts, which continue feeding warm humid air into a spreading thunderhead cloud.
It is during this most violent time in the thunderstorm that a tornado may form at the edge of the updraft, where it meets the downdraft. The updraft pulls air away from the ground, which creates an area of low pressure.
More air rushes in to take the place of air that's been pulled up. Then the falling water droplets in the downdraft get swept in and begin to form the tornado's funnel shaped cloud. As the swirling winds pick up dirt and materials from the ground, the funnel grows darker.
ACTIVITY #1-Tornado In A Bottle
Students will demonstrate and understand the principals of a vortex, observe and simulate a tornado and understand the weather phenomena of how a tornado originates.
ACTIVITY #2-Tornado Air Movement
Discover how air moves inside a tornado using Glitter.
Try Dorothy's recipe for a Twister in a bottle.
Answer the questions on Why Files Twister Page.
Follow the hyper links to answer the questions.
Exploratorium - Vortex in a bottle.
Check out other interesting weather phenomena and topics from about.com
***** Now view a quicktime movie clip to see the real thing! *****
For a 972 Kb Quicktime Tornado Movie
Click here to download a Quicktime Player for PC or Mac
When a tornado touches down, it creates an explosion of dust and wreckage on the ground. One monster tornado that touched down in Illinois in 1990, picked up a 20-ton truck and deposited it in a field over eleven hundred feet away. Strong tornadoes can easily pick up houses and move them hundreds of feet from their original locations. Tornadoes have been known to pick up turtles and frogs from ponds and drop them coated with ice like hailstones in neighboring towns. Powerful tornadoes can uproot trees and break their trunks in half. They also have the capability of hurling debris with such force that the materials can penetrate concrete.
Follow this link to see How tornadoes are rated.
The Fujita-Pearson Tornado Intensity Scale ranks tornadoes according to their wind speed and the kind of damage they can cause. So grab a calculator, a pencil, and sheet of paper and visit DISASTER MATH.
DISCOVERY TASK: Check your monstrous "math speed" and accuracy and see how much damage you can do on these problems.
COME AGAIN, STORM CHASERS!
Computer with Internet access
Materials to complete lab activities and discovery tasks
Created August 6, 2001
Last Revised November 7, 2001
Suggested Grade Level: 6
Science Content Standards:
Grade 6: S.C.O.R.E. Lesson Standards (Earth Science 3a, 4e)
Investigation and Experimentation (7a,b,c,d,e,g)
S.C.O.R.E. Lessons Standards Search by Grade and Subject
S.C.O.R.E. Standards and Framework
California Content Standards Grades K-12
California Content Standards Grades K-12 - Science - PDF Format
Students need a basic background in lab procedures, the scientific method, and cooperative team work. (timekeeper, supplies, clean-up).
Time: (Total 3-4 45 minute class sessions)
Activity Lab Worksheet Criteria using "scientific method" approach:
Title of lab Problem/Question
Diagram (of lab set-up) *optional
Results (graphs, charts, tables...)
Research material *optional
Interpreting data, making inferences, making predictions, graphing, math problem solving,
diagramming, timing an action, observation, sequencing
Communication of ideas: verbal and writing format
Effective use of Internet resources
On the activity labs, a rubric can be used. Factors for consideration are: labs reports are complete, the scientific method is used, data is well organized, work is neat, and accurate grammar and spelling is used
Student assessment and/or degree of engaged involvement may be used on other "discovery tasks."
Although we don't really notice it much, air is all around us and is pressing on everything all the time. Air pressure is caused because air has weight and it is pulled down to Earth by gravity. As it is pulled down it squeezes against things - creating AIR PRESSURE. Slight changes in air pressure give us a clue about weather changes. We can measure air pressure and predict the weather with an instrument called a BAROMETER.
WEATHER FORECASTING - MAKING A BAROMETER
1-new balloon 1-clean glass jar 1-drinking straw
1-toothpick 1-rubberband 1- 9x18 piece of cardboard
a piece of paper
(1) Cut the neck off the balloon. Stretch the balloon over the jar and hold it in place with the rubber band.
(2) Tape the toothpick to the end of the straw. Tape the other end of the straw to the center of the balloon lid. Make a weather picture chart on the piece of paper, with "good weather "marked at the top.
(3) Make a 1/3 section fold on the piece of cardboard (and cut a triangle to form a support on the back), set the glass jar on the cardboard, position the weather picture chart centered directly across from the end of the toothpick and watch to see if the pointer moves a little each day.
(1) Check the movement of the barometer with that day's weather and determine if there is "greater or less" air pressure on a sunny weather day versus an overcast or rainy day. DISCOVERY = Sunny days require _________ air pressure. (greater/less) EXPLAIN in your science journal how your activity proves your "discovery "statement.
(2) Now go ahead and collect air pressure data for a week (or month) and make a line graph with your results.
WARM AND COLD AIR COLLISIONS
2-quart (sized) glass jars, 1-pan of hot water, hemp rope (or incense), ice cubes (enough to fit on bottom of one glass jar) 1-flashlight, 1-match.
(1) Put one jar upright in the pan of hot water.
(2) Have your teacher put smoke in the two jars.
(3) Then stand the second jar upside down on the first bottle with the mouths of the jar together.
(4) Put several ice cubes on top of the upper jar.
(5) Darken the room.
(1) Use the flashlight and observe the movement of the smoke.
DISCOVERY = The air in the bottom jar being heated will ____. When it near the top of the second bottle, it will cool and begin to ___________________. Air currents will ___________________ in the two jars. (cool/rise/swirl)
INTERNET SOURCE ACTIVITIES:
Web Weather for Kids - Tornadoes
(First activity is excellent for a teacher demonstration)