1. Learning objectives Why do geographers study the weather?
What is the difference between 'weather' and 'climate‘?
Climate graphs
Why does it rain?
Learning objectives

2. Why do geographers study the weather?
The weather has an impact on many of the things that we do! Can you explain how the weather affects these people?
Images represent – doctors, drivers, shopkeepers, builders, tour operators and farmers. There are of course many more groups that could have been included…
Opportunity to ask pupils to come up with other reasons as to why the weather is important?
The ‘weatherwise’ section of the BBC’s website is a good site for further information

3. Learning objectives Why do geographers study the weather?
What is the difference between 'weather' and 'climate'?
Climate graphs
Why does it rain?
Learning objectives

4. What is the difference between weather and climate?
Climate is the overall average pattern of weather and is usually measured on a larger scale (continents, world)
Altitude
Latitude
Oceans, Lakes,
Rivers
Precipitation
altitude, latitude, water bodies, precipitation, prevailing winds, topography
Topography shape, height, depth of land
wind direction

5. The same heat has further to travel near the poles of the earth
Heat is more
Concentrated at the
Equator
The same heat has further to travel near the poles of the earth
Latitude

6. Title the Map and color it according to the photo below

7. Elevation (altitude) Effects on Climate

9. Title the Map and color it according to the photo below

10. Temperature and Rainfall effects Climate
Climate graphs are a way of showing how temperature and precipitation vary throughout the year for a particular place.

11. Climate chart for Queen Creek Arizona

12. Plot your own climate graph
Month
Jan Fe Ma
Apr
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Rainfall (in)
0.91
Temp
(0F)
56.5
Queen Creek, Arizona
Use this data to draw a climate graph for Queen Creek.
Graph should be titled (x axis, y axis, and main title)
Line Graph for Temp (in red)
Bar graph for Precipitation (in blue)
Number Y axis to 100 degrees F
Label the X axis the months of the year J F M A

13. Plot a Climate Graph for Cape Town
Month
Jan Fe Ma
Apr
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Rainfall (in)
0.82
0.86
1.25
2.83
4.7
5.7
5.11
4.9
2.76
2.16
1.18
0.98
Temp
(0F) 68 69 67 60 55 52 49 45 48 53 58
Cape Town, South Africa
Use this data to draw a climate graph for Cape Town.
How does it compare to this climate graph of Queen Creek?
What makes it’s climate different?

14. Look at your maps and notes
Clearly their day to day weather changes
What OTHER factors did you learn about today that effects Cape Town and Queen Creeks Climate?

15. Learning objectives Why do geographers study the weather?
What is the difference between 'weather' and 'climate‘?
Climate graphs
What is precipitation?
Why does it rain?
Learning objectives

16. What is precipitation? Precipitation is water from the atmosphere.
It can be in solid or liquid form.
Name as many different types of precipitation as you can!
An opportunity to make a list of as many types of precipitation as possible:
Rain
Hail
Sleet
Snow
Fog
Dew

17. Learning objectives Why do geographers study the weather?
What is the difference between 'weather' and 'climate‘?
Climate graphs
What is precipitation?
Why does it rain?
Learning objectives

18. Why does it rain? Warm moist air rises.
There are three main types of rainfall – relief, convectional and frontal.
Why does it rain?
Warm moist air rises.
As air rises it cools and condenses.
Condensed/cooled air forms mini droplet that become to heavy and falls.

19. Convectional rain

20. Convectional rain

21. Relief rain

22. Relief rain

23. Frontal rain

24. Key Ideas
Geographers study the weather because it has an impact on people’s daily lives and the activities that they do.
Weather is the day to day changes in the atmosphere.
Climate is the overall average pattern of weather
Precipitation is water from the atmosphere.
It can be in solid or liquid form.
There are three main types of rainfall – relief, convectional and frontal. In all three situations, rainfall occurs because air is forced to rise.

25. Weather and Climate Unit Investigative Science
The Nature of Storms
Weather and Climate Unit
Investigative Science

26. What do You Think?

27. At any given moment, nearly 2000 thunderstorms are in progress around the world.
Most do little more than provide welcome relief on a muggy summer afternoon, or provide a spectacle of lightning.
Some, however, grow into atmospheric monsters capable of producing hail the size of baseballs, swirling tornadoes, and surface winds of more than 160 km/hour.
These severe thunderstorms can also provide the energy for nature’s most destructive storms—hurricanes!
Thunderstorms

28. How Thunderstorms Form
The stability of air is determined by whether or not an air mass can lift.
Cooling air masses are stable.
Air masses that are warming from the air or land beneath them are not stable.
Under the right conditions, convection can cause a cumulus cloud to grow into a cumulonimbus cloud.
The conditions that produce a cumulonimbus cloud are the same conditions that produce thunderstorms.
How Thunderstorms Form

30. Three Conditions Needed for a Thunderstorm to Form
For a thunderstorm to form, three conditions must exist:
1) a source of moisture
2) lifting of the air mass
3) an unstable atmosphere
Three Conditions Needed for a Thunderstorm to Form

31. For a thunderstorm to form, there must be an abundant source of moisture in the lower levels of the atmosphere.
Air masses that form over tropical oceans or large lakes become more humid from water evaporating.
This humid air is less dense than the surrounding dry air and is lifted.
The water vapor it contains condenses into the droplets that make up clouds.
Latent heat, which is released from the water vapor during condensation, warms the air.
This causes the air to rise further, cool further and condense more water vapor.
Moisture

32. As moisture condenses into clouds, it releases its latent (stored) heat.
This occurs when a warm air mass is lifted into a cooler region of the atmosphere.
Dense, cold air along a cold front can push warmer air upward.
Warm land areas, heat islands such as cities, and bodies of water can also provide heat for lifting an air mass.
Only when water vapor condenses can it release latent heat and keep the cloud rising.
Lifting

33. If the surrounding air remains cooler than the rising air mass, the unstable conditions can produce clouds that grow upward.
This releases more latent heat and allows continued lifting.
When the density of the rising air mass and the surrounding air are nearly the same, the cloud stops growing.
Cumulus clouds can become cumulonimbus clouds as the air mass rises, cools, releases more heat, rises, cools again—over and over.
Unstable Atmosphere

35. Air Mass Thunderstorms
Air near surface is warmed during the day.
Warm air rises and condenses to form cumulous clouds in the afternoon.
Scattered, isolated.
Most moisture evaporates
but eventually it accumulates into
taller clouds.
Air Mass Thunderstorms

36. Forms along a Cold Front

37. Or…along a Warm Front
Unstable air mass

38. Orographic lifting over mountains

39. Forms when air converges, is forced up, cools adiabatically, form clouds
These tend to be brief, short-lived storms with moderately heavy downpours.

40. 3 Stages of Development of a Thunderstorm
Pg. 288

41. Stage 1
Cloud continues to grow as long as there is a supply of warm, moist air.
Updraft occurs.

42. Bergeron Process Ice crystals collect water molecules and grow larger
while cloud droplets evaporate and get smaller. 42

43. Stage 2
Mature stage

44. Stage 3

45. Developing
Cumulonimbus
Fair-Weather Cumulus

46. Well-Developed Cumulonimbus

47. Severe Thunderstorm Development along a Cold Front

48. Roll
Cloud

49. Average Number of Thunderstorm Days

50. Atmospheric
Hazard
Flash Floods - Number One Thunderstorm Killer

51. Supercell Thunderstorm
A single, very large
(65,000 ft. high) massive cloud miles in diameter,
Lasts for many hours

52. Cluster of Supercell Thunderstorms

53. Temperature Inversion enhances formation of severe thunderstorms: dense, cold layer above prevents warm, moist air from rising.
Surface air heats up, and finally erupts upward, producing an unusually large cumulus cloud 53

54. Mammatus
Sky

55. Microburst http://www.youtube.com/watch?v=fjFTH3s6BlM
Strong DOWNDRAFTS
Beneath the thunderstorm
Small 2.5 miles across
Cold dense, sinking air
Last 2-5 minutes
Also called wind shears