Climate maps / synoptic charts

1. What is a synoptic chart

A map giving a summary of the weather conditions at a particular time and place

2. Time that synoptic maps are published

12:00 Zulu time or 14:00 SA standard time (Add 2 hours to UTC)

3. Why are synoptic maps important

Allows for weather preditction which lets people prepare for flooding from rainfall or evacuation

4. Main South African Weather stations

Gough Island, Marion Island and Tristan da Cunha

5. Why does South Africa use Marion Island for the weather station

Allows us to see and predict incoming weather conditions in order to create a forcast

6. Summer Solstice

21 December

7. Autumnn solstice

21 March

8. Winter solstice

21 June

9. Spritng solstice

22 September

10. What is an isobar

A line which joins areas of the same barometric pressure

11. Why is the pressure pattern of isobars important

1. Where the wind is coming from. 2. How strong the wind is. 3. Areas of high and low pressure

12. Air moves from

High to low pressure along a gradient

13. Isobars that are very close together

Strong winds

14. Intervals of Isobars

4hPa

15. (Low pressure zones) Atmosphric pressure of a low pressure zone

Less than 1013 hPa

16. (Low pressure zones) Another name for low pressure zones

Depressions/cyclones

17. (Low pressure zones) Movement of low pressure cells in the Southern hemisphere

LIRC. LOW pressure. Air is sucked INWARDS. Air RISES which results in clouds. Air moves towards the centre in a CLOCKWISE motion and cells form a spin (this spin can cause hurricanes and cold fronts)

18. (Low pressure zones) Movement in the northern hemisphere

Air moves anti-clockwise due to the coriolis force

19. (Low pressure zones) Weather conditions of a low pressure zone

Rain, clouds, windy (Low-sy weather, air is rising and therefore forms clouds)

20. (High pressure zones) Atmospheric pressure of a high pressure zone

More than 1013 hPa

21. (High pressure zones) Another name for high pressure zones

Anti-cyclones

22. (High pressure zones) Movement of high pressure cells in the southern hemisphere

HASO. HIGH pressure. Air moves ANTICLOCKWISE. Air is SINKING (warm cloudless weather). Air is moving OUTWARDS.

23. (High pressure zones) Movement of high pressure cells in the northern hemisphere

Clockwise due to the coriolis force

24. (High pressure zones) Weather conditions of high pressure zones

Clear skies (air is pushing down), littlw wind (Heavenly weather)

25. Descending air diagram

High pressure zone, air sinks/subsides

26. Ascending air diagram

Low pressure zone, air is rising/ascending

27. (Pressure cells) High pressure cells names

South atlantic high pressure cell (on the left of SA), South Indian high pressure (on the right of SA) and Kalahari high pressure (on the land, indicates winter)

28. (Pressure cells) Factors causing high pressure

1. Altitude, 2. Temperature, 3, Season, 4.Water vapour, 5. Type of movement

29. (Factors causing high pressure) Altitude

Sea level means there is more air, there is more weight / pressure pushing air down

30. (Factors causing high pressure) Temperature

Cold air sinks

31. (Factors causing high pressure) Season

In winter it is cold and therefore the air is heavier

32. (Factors causing high pressure) Water vapour

Dry air is heavier

33. (Factors causing high pressure) Type of movement

Divergence, the air sinks and goes out (diagram)

34. (Pressure cells) Factors causing low pressure

1. Altitude, 2. Temperature, 3, Season, 4.Water vapour, 5. Type of movement

35. (Factors causing low pressure) Altitude

The higher the area the less air there is and air pressure decreases

36. (Factors causing low pressure) Temperature

Warm air rises

37. (Factors causing low pressure) Season

Summer means that it is warmer and miore air is rising

38. (Factors causing low pressure) Water vapour

Higher humidity means more clouds

39. (Factors causing low pressure) Type of movement

Convergence, air moves upwards and meets to form clouds (diagram)

40. Temperature

refers to how hot or cold it is

41. Temperature measurement

Using a thermometer and is represented in degrees celsius

42. Precipitation

Refers to any form of moisture that falls from the sky

43. Forms of precipitation

Rain, hail, snow

44. Rain

Water droplets that fall from the sky

45. Rainfall measurement

Measured using a rain gauge and is represented in millimeters

46. Wind

moving air

47. Meteorolgists meausure wind

The direction and speed

48. Wind direction

Determined using a wind vane or wind sock

49. Wind speed

Meaured using an anemometer and is recorded in knots (intervals of 5)

50. Cloud cover measurement

No instrument, is done with eyes

51. Expression of cloud coverage

In eights, never simplify

52. Cloud coverage indication

Of what weather to expect

53. Elements that weather station models measure

Precipitation, Temperature, wind speed, wind direction, cloud cover

54. Weather station model

A symbolic illustration of the weather occuring at a given reporting station compiled by meteorologist

55. Wind pressure is measured

Using a barometer

56. ⅛ Cloud cover

line in the middle of circle

57. 2/8 cloud vover

quarter of the circle

58. 4/8 cloud cover

half of the cirlce

59. 6/8 cloud cover

three quarters of the cirlce

60. 8/8 cloud cover

full cirlce

61. Sky obscured

x over the cirlcle

62. Max temperature

top number

63. Dew point

bottom number

64. Weather

64. middle dot with a symbol

65. Wind speed

feathers

66. Wind direction

is dependant on where the wind is going

67. Wind name

Depends on where the wind is coming FROM

68. Wind speed 10 knots

69. Wind speed 15 knots

70. Wind speed 5 knots

71. Drizzle symbol

72. Fog or mist symbol

73. Hail symbol

74. Rain symbol

75. Shower symbol

76. Sleet symbol

77. Snow symbol

78. Thundestorm symbol

79. Max temp and dew point close together

higher chance of rain

80. Who needs to understand the weather

pilots, ships, sporting, farming, construction (safety)

81. Steps to read a synoptic chart

Find south africa, find the date (indicates season), find the time, key

82. Influence of oceans on the areas adjacent to them

Warm agulhas on east causes ait to be warmer, humid, and unstable thus increases the rainfall. Cold on westcoast due to benguela, air above the ocean holds little moisture anf therefore fog can form with very little rainfall

83. Influence of latitude

Type of high pressure zones. South atlantic high, kalahari high, south indian high

84. South Atlantic high pressure

Causes stable conditions on west coast, can ridge in behind the front and pushes a cold front across the land (WC). Elongated air mass pushes air

85. South Indian high pressure

Causes north easterly or south easterly onshore winds (warm air from agulhas current is pushed onto the land). Brings rain to the eastern sude and is further from the land in summer but moves closer in winter

86. Kalahari high pressure (inland high pressure)

Lower in winter as the mass is cold and less air is rising, clear skies no rain in winter - leads to frost. ONLY IN WINTER . (Don’t receive warm air from agulhas over the plataeu because of the khp)

87. Cold front shape

88. Warm front shape

89. Cold fronts

Moves from the west in an easterly direction across SA

90. What happens when cold air behind the front reaches the warm air in front

storms and rains occur (eg capetown rain in winter)

91. Temperature of front

Follows BEHIND the front

92. Troughs drawing (elongated lp)

93. Troughs

An elongated low pressure cell that is often associated with cool, cloudy and potentially wet weather (severe rainfall)

94. Ridge drawing

95. Ridge

An elongated area of high pressure, typically associated with warmer, drier and fair weather and can bring about heat waves