3. a large body of air that has the same temperature and humidity throughout classified according to where they originate during the time the air mass is over an area, it determines the weather of that area

4. Originates over the ocean  humid air mass (m) (maritime)

5. Originates over the land  dry air mass (c) (continental)

6. Originates in cold air  cool air mass (P) (Polar)

7. Originates in warm air  warm air mass (T) (Tropical)

9. small balloon carried observatory that carries a radio transmitter that sends out signals about air pressure, temperature, and humidity

10. fronts: boundary between two air masses having different temperatures and humidity

11. warm air overtakes cool air warm air rises brings hot, humid days and precipitation over a large area

13. cold air overtakes warm air cold air forces warm air up brings strong storms (squall) with clear days following

15. two cold masses sandwich a warm mass warm air rises between them brings strong winds and heavy rains

16. does not move

17. small-area storms formed by the strong upward movement of warm, moist, unstable air always accompanied by lightning, thunder, and usually rain formed from cumulonimbus clouds

18. Air-mass thunderstorm: form in warm, moist air mass occur in spring and summer- last less than 1 hour single, widely scattered

20. Frontal thunderstorm: occur in lines along a frontal surface stronger and may last several hours can produce heavy rain and flooding

21. Lightning: a discharge of electricity from a thundercloud to the ground, or cloud to cloud, or ground to cloud

22. temperature inside lightning flash can reach 28,000°C at this temperature, air expands explosively-sudden expansion makes thunder!

25. an intense tropical low- pressure area with sustained winds starting at 75 mph

26. storm surge: currents formed when hurricanes pile water up along the shore and blow it inland most damaging part of a hurricane

29. eye: central area of sinking air; 15 to 20 km wide

30. Winds most violent just outside the eye

31. http://www.weather.com/web/newscenter/specialreports/ hurricanes/inside/elements.html Check out this website!

32. Tropical depression: wind speeds up to 38 mph; some circular rotation at surface

34. Tropical storm: wind speeds from 39-74 mph; can be named, shows drop in pressure, distinct rotation

36. Hurricane: wind speeds up to 75 mph

38. Movement of Air in a Hurricane

39. A schematic of this banding feature can be seen in the diagram above. The thunderstorms are now organized into regions of rising and sinking air. Most of the air is rising, but there is a small amount found in between the thunderstorms that is sinking.

48. a narrow, funnel-shaped column of spiral winds that extends downward from the cloud base and touches the ground

49. strongest winds between 360 and 500 km/hr funnel less than 500 m across always travel with a parent thunderstorm at speeds ranging from 40 to 65 km/hr

50. funnel is a mixture of clouds and dust pressure gets lower in center air flows toward the funnel and cools to dew point- drops form lowering of condensation level due to low pressure causes cloud to funnel Extremely low pressure-when it touches ground, acts like a giant vacuum

51. Waterspout: tornados over the water- weaker than tornados

53. Tornados usually occur during spring and summer and most likely occur in late afternoon

56. Fujita Scale: scale used for categorizing tornados

58. Meteorologists interpret weather information from: satellites commercial aircraft weather balloons

59. weather stations around the world Radar: electronic device that transmits radio waves in the form of a beam

61. Data is collected and put into a central computer at the National Weather Service data includes: winds, temperature, pressure, humidity, clouds, precipitation Makes a computer model (copy of the atmosphere in computer

62. Maps are made and forecasts are reported to local stations across the country Weather forecasts are issued by the Weather Service at 10 am, 4 pm, 9pm, and 4 am. Forecasts are updated more often during severe weather.

63. watch: threat of storm conditions within 24-36 hours warning: due to strike within 24 hours