1. front

2. Where air masses meet and do not mix.

3. warm front

4. the leading edge of a moving mass of warm air.

5. stationary front

6. when a cold and a warm air mass meet, but neither moves.

7. stratus

8. lower level; layered-looking clouds.

9. condensation

10. the process by which a gas becomes a liquid. Water vapor turns into liquid water by condensation.

11. evaporation

12. the process by which a liquid becomes a gas.

13. run-off

14. the flow of water, from rain, snowmelt, or other sources, over the land.

15. saturated

16. thoroughly full.

17. watershed

18. an area of land that is drained by a stream or river and its branches.

19. temperature

20. a measurement of the amount of heat a substance contains.

21. stratus

22. a cloud belonging to a class characterized by horizontal layering with a uniform base. More specifically, the term stratus is used to describe flat, featureless clouds of low altitude varying in color from dark gray to nearly white.cloud

23. prevailing winds

24. the trends in speed and direction of wind over a particular point on the earth's surface.windearth

25. Westerlies

26. Any semipermanent belt of westerly winds, especially those that prevail at latitudes lying between the tropical and polar regions of the earth

27. Easterlies

28. A storm or wind coming from the east

29. pattern

30. a repeating arrangement of shapes, colors, numbers, or other things.

31. air mass

32. a body of air that has the same temperature and/or humidity throughout.

33. air pressure

34. the pressure exerted by air per-unit surface area in the earths atmosphere. Also called barometric pressure.

35. almanac

36. a publication that contains astronomical and meteorological data and forecasts.

37. aneroid barometer

38. a barometer that does not require the use of a liquid.

39. atmosphere

40. the layer of air that surrounds the earth.

41. barometer

42. a device used to measure air pressure.

43. beaufort scale

44. a scale that relates the wind speed to its effects booth on land and at sea, classified from force 0 to force 12.

45. cirrus

46. high level clouds made mostly of ice crystals.

47. climate

48. the average weather over a long period of time.

49. cumulonimbus

50. clouds that bring summer storms, usually with thunder, lighting, and strong winds.

51. cumulus

52. mid-level, puffy clouds.

53. fog

54. clouds that form at ground level.

55. forecast

56. a prediction of the weather conditions for a given area and a given time period.

57. hurricane

58. a large rotating windstorm with a calm central eye and winds greater than 118 kph.

59. isobar

60. lines drawn on a weather map that connect areas of the same barometric pressure at a given time.

61. meteorologist

62. a person who studies meteorology.

63. meteorology

64. the study of the earths atmosphere and what happens in it.

65. occluded front

66. where a cold front catches up to and overtakes a warm front.

67. precipitation

68. any liquid or solid form of water that falls from the atmosphere. For example, rain, snow, hail, or sleet.

69. rain gauge

70. a device used to measure the amount of precipitation in a given area.

71. station model

72. a weather symbol that represents the state of the weather at a particular place.

73. stratus

74. lower level; layered-looking clouds.

75. tornado

76. a narrow, violently rotating column of air characterized by winds greater than 81 kph and a funnel cloud that reaches the ground.

77. vacuum

78. an area of no air pressure.

79. weather

80. the state of the atmosphere at a given time and place with respect to wind, temperature, cloudiness, moisture, pressure, and other factors.

81. weather forecasting

82. predicting what future weather will be like.

83. weather front

84. the boundary where difficult air masses collide.

85. weather station

86. a place where weather data are recorded.