The document provides information about various weather phenomena including: 1) Thunderstorms form from mature cumulonimbus clouds and can produce heavy rain, lightning, hail and tornadoes. 2) Tornadoes are rotating columns of air that extend from storm clouds to the ground and have wind speeds up to 300 mph. 3) Tropical cyclones like hurricanes are large storm systems that form over warm ocean waters and contain heavy rain and high winds. They can last for many days.

1. Intro to Weather Clip

2. Weather by Brainpop
1) What cycle is the basis of
our weather?
2) What causes precipitation
to occur?
3) Where do storms usually
occur?

3. Weather
 Temporary behavior of atmosphere
(what’s going on at any certain time)
 Small geographic area
 Can change rapidly

4. Weather
--The study of weather is
meteorology
--Someone who studies weather is
called a meteorologist

5. Climate
 Long-term behavior of atmosphere
(100+ years)
 Large geographic area
 Very slow to change

6. POLAR
90o -60o latitude
Cool summers, cold year-round
Dry

7. TEMPERATE
60o-30o latitude
True Seasons
Variety of climate patterns
Moderate precipitation (rain/snow)

8. TROPICAL
30o - equator
No winter, warm year-round
High temp, rainfall, humidity

9. Climate Types by Brainpop
1.What is climate?
2.Where are tropical
climates most likely to be?
3.What does “arid” mean?

10. What Factors Affect Weather
& Climate?
1. The Sun
2. The Water Cycle
3. The Atmosphere
4. The Ocean

11. How Does the Sun Affect
Weather?
It warms the atmosphere &
oceans
It creates climate zones
It keeps the water cycle
going
It affects weather patterns

12. The Water Cycle
All the water on the planet is recycled in
this manner!

13. Parts of the Cycle
Evaporation—Water going
from a liquid to a gas (gains
energy from the sun)

14. Parts of the Cycle
*Transpiration—evaporation of water
from/out of plants. Locate this on the
diagram!
transpiration

15. Parts of the Cycle
Condensation—Water going from a gas to a
liquid (cools or loses energy)
 When this happens in the atmosphere,
CLOUDS form.

16. Clouds by Brainpop

17. Parts of the Cycle
Precipitation—when water falls out the
atmosphere. Forms when the water
droplets in clouds become too heavy to
stay up.

18. Precipitation
Liquid water = rain
Frozen water = snow
or sleet or hail
Rain Clip

19. The Water Cycle
Water Cycle by Brainpop

20. Water Cycle Advanced by Brainpop

21. The Water Cycle by Brainpop
1) What process must happen
for clouds to form?
2) What is “collection”?
3) Name one way to conserve
water.

22. How does the atmosphere
affect weather?
The atmosphere is a mixture of
gases that surrounds the Earth
Has five different layers; each has
different properties
We’ll label them in just a minute…
Air Temperature and Pressure
change with altitude
Weather occurs in the layer closest

23. Troposphere
Stratosphere
Mesosphere
Ionosphere
Exosphere
Thermosphere
Write in the
labels!
Ozone layer

27. Earth’s Atmsophere by Brainpop
1. What is ozone?
2. What layer of the
atmosphere does weather
occur in?
3. What 2 gases compose the
most of Earth’s Atmosphere?

28. Air Masses
= body of air with a
certain temperature and
moisture level
Can be warm or cold
Can contain a lot of
moisture or not a lot of

29. Fronts
= places where
air masses meet
4 Types: Warm,
Cold, Occluded,
Stationary
Each kind can
bring different
kinds of weather

30. Occluded Front: Stationary Front:

32. Science Saurus 221/222
& Reading a Weather
Map Worksheet

33. How does Air Pressure
affect weather?
How much the earth’s atmosphere is
pressing down on us
Measured with a BAROMETER
If it CHANGES, then new weather is on
the way:
Falling Air Pressure = stormy weather
coming
Rising Air Pressure = fair weather coming

34. Pressure Systems

35. Winds = created from
differences in air pressure
Moves from areas of HIGH to LOW
pressure
Greater the difference in pressure, the
FASTER the wind blows
Measured with wind vanes and
anemometers or you can estimate with
the Beaufort Wind Scale
ScienceSaurus 224/225

36. Beaufort Wind Scale

37. Global Winds
Thousands of kilometers long;
can cause weather to move in
different directions
Jet stream, prevailing westerlies,
doldrums, horse latitudes, trade
winds Big Winds Blowin’ Worksheet &
Science Saurus Section 217

38. Global Winds
Caused by the temperature
difference in different regions
 Hot Tropical Regions—causes air to
rise
 Cold polar Regions—causes air to
sink

39. Global Winds
Also affected by Earth’s Spin
 Coriolis Effect = causes winds to
curve to the right in the N.
Hemisphere; to the left in the S.
Hemisphere

40. Big Winds Blowin’ Worksheet

41. Winds by Brainpop
1. What does warm air do?
2. What do you call winds
that blow all the time in the
same part of the world?
3. What are jet streams?

42. Relative Humidity
 Measure of the amount of
moisture in the air compared
to what the air could hold
 How “full” of water the air is
 Expressed as %
 100% relative humidity =
saturated air
Relative Humidity Test Applet
http://itg1.meteor.wisc.edu/wxwise/relhum/rhac.html

43. Relative Humidity
Controlled by temperature
1. Warm air holds more moisture than
cool air (more space for water vapor
between air molecules)
2. As air warms, relative humidity
decreases
3. As air cools, relative humidity
increases

44. Dew Point
 =Temperature at which the air is
saturated (100% relative humidity)
Several events can occur when the dew
point temp. is reached:
1. If dew point temp. is above
freezing:
a. water vapor condenses as liquid
b. dew will form on surfaces

45. Dew Point
c. cloud droplets will form in air
2. If dew point temp. is below freezing:
a. water vapor condenses as a solid
b. frost on surfaces
c. snow (or hail) in the air

46. Humidity by Brainpop
1. What single factor controls
humidity?
2. What temperature air can
hold the most water molecules?
3. What causes water to
evaporate into the

47. Rainbows
 Caused by sunshine on raindrops
 White light (all colors) is refracted
(bent) into colors as it enters and exits
the drop
 To see a rainbow you must have the
sun behind you and raindrops in the
air
 Diagram:

48. Rainbow by Brainpop

49. How does the Ocean
affect weather?
Ocean currents affect the temperature
of the land they pass by
Cold ocean currents = cooling effect
Warm ocean currents = warming effect
Temperature changes affect pressure –
which then creates WINDS
Winds blow this cooling or warming
effect over the land
http://earth.rice.edu/MTPE/hydro/hydrosphere/topics/Ocean_Atm_Circ_ElNin

50. http://www.wunderground.com/MAR/

51. Science Saurus Sections 203-204-205-206

52. Advanced Weather by
Brainpop
Violent Weather

54. Thunderstorms
Requires a mature cumulonimbus
cloud
Signs
a. Sudden reversal of wind
direction
b. Noticeable increase in wind
speed

55. Possible weather:
a. heavy rains (flash floods)
b. lightning (forest fires)
c. thunder (frightens animals)
d. hail (crop damage)
e. tornadoes
f. strong, gusty winds
Thunderstorm by Brainpop
Thunderstorms

56. Safety Rules
 Stay indoors
 Prepare for lightning, strong winds
 Listen on radio/TV for tornado
watch/warning
 Thunderstorms don’t last long

57. Lightning Storm
Cumulonimbus cloud becomes
electrically charged and ground below
has opposite charge

59. Lightning stroke: flow of current thru air
(a poor conductor) from the – to the +
Lightning can flow from cloud to
ground, cloud to cloud, and from
ground to cloud
Bright light is caused by glowing air
molecules heated by the current
Lightning follows the path of least
resistance (easiest way to positive)
Lightning rod offers lightning an easy,
safe path to the ground (+)

60. Thunder is the shock wave caused by the
explosive expansion of heated air
Sound travels @ about 1100 ft/sec in
air
5,280 ft in one mile
Distance from you to lightning =
number of seconds between seeing the
flash and hearing the thunder divided
by 5.

61. Types of Lightning
Streak or bolt
a. Single or branched lines of light
b. Common in Puget Sound area

62. Sheet
a. shapeless flash over wide area
b. is cloud-to-cloud bolt hidden by the
clouds
c. common in Puget Sound area

63. Other types of lightning
a. heat, ribbon, beaded (types of bolt)
b. ball (only other shape lightning can
have)

64. Safety rules for lightning storms
 Stay indoors
 Stay away from anything that conducts
electricity (stove, sink, telephone, TV)
 Get out of the water and off of small boats
 Stay away from open doors, windows,
fireplaces
 Stay in your car (very safe place to be)
 Don’t stand under lone trees or in open
places
 Avoid hilltops
 If your hair stands on end, or your skin
tingles, drop to the ground but try to keep

65. Lightning Strikes
(17 minutes)
Stories of people hit by
lightning

66. Tornado (a.k.a twister,
cyclone)
 Counterclockwise column of rotating
air extending from cumulonimbus
cloud
 Per square foot, is the most
destructive atmospheric event
 Rated by wind speed (F1 to F5)
 “Tornado season” = April, May, June
 Tornadoes that form over water are
called “waterspouts”

67. Behavior of a tornado is unpredictable
Typical tornado will:
1. Occur between 3-7 pm
2. Travel 4 miles
3. Be 300-400 m wide
4. Travel 25-40 mi/hour
5. Have wind speeds up to 300 mi/hr
6. Produce extremely low pressure
7. Be dark due to debris picked up
Tornado by Brainpop

68. Safety Rules
 Rule #1: Take immediate action!
 Move away from tornado’s path
Tornado’s path
Move away at a right angle

69. Lie flat in nearest ditch, etc.
At home
a. open windows, doors
b. seek shelter in basement or under
heavy table in middle of house
On the trail of a tornado

70. Tropical Cyclone
Nicknames
1. Atlantic: hurricane
2. SE Asia, Japan: typhoon
3. Australia: willy-willy
4. Indian Ocean: cyclone

71. Tropical Cyclone
Rated by wind speed (category 1 to 5)
Starts and grows over warm ocean
water
Composed of bands of thunderstorms
spiraling counterclockwise around a low
pressure center

72. Characteristics
 Several hundred miles wide
 Last many days (even weeks)
 Winds from 74-200 mi/hr
 Contains an “eye”
a. Small region of low pressure
b. Surrounded by highest winds
c. Calm, peaceful, sunny weather
d. Last for about 1 hour as hurricane passes
by
Hurricances by Brainpop

73. Safety Rules
 Prepare for high winds
 Prepare for flooding (greatest source
of damage)
a. Up to 20 in. of rain
b. Flooding by coastal water
 3. Prepare for thunderstorms
 4. Have on hand stored food, water,
blankets, candles, matches, radio, etc.
 5. Seek shelter
Hurricanes Clip