Weather Maps

4. Air masses that originate over an ocean.
8. Two cold air masses converge on a warm air mass.
9. The average barometric pressure at sea level is 29.92 inches of _______ (Hg).
10. The boundary between two air masses.
11. The average barometric pressure at sea level is 1013.25 _______ (mb).
13. A tool that helps determine wind direction on a weather map.
14. A tool that measures wind direction.
17. Air masses that originate over a continent.
19. A warm air mass is replacing a cold air mass.
20. A cold front that approaches from the east or northeast.
21. Pressure caused by the weight of air above an area

1. A tool that measures temperature.
2. A boundary between two different air masses, neither of which is strong enough to replace the other.
3. This pressure causes happy weather (clear skies, calm winds, dry air).
5. This pressure causes lousy weather (cloudy skies, strong winds, humid air).
6. Balloon A tool that carries other instruments to high altitudes.
7. A line connecting points of equal atmospheric pressure on a weather map.
12. A cold air mass is replacing a warm air mass.
15. A tool that measures wind speed.
16. A tool that measures atmospheric pressure.
18. A large body of air that has relatively uniform temperature and humidity.