Chapter 24 Section 2 Handout

1. Chapter 24 Section 2 Handout Fronts

2. 1 • When two unlike air masses meet, what usually keeps them separate? • Differences in density

3. 2 • The boundary that forms between two air masses when they meet is called a: • Front

4. 3 • Cold front: • The front edge of a moving mass of cold air that pushes beneath a warmer air mass like a wedge.

5. 4 • Warm front: • The front edge of an advancing warm air mass that replaces colder air with warmer air.

6. 5 • Stationary front: • A front of air masses that moves either very slowly of not at all.

7. 6 • Occluded front: • A front that forms when a cold air mass overtakes a warm air mass and lifts the warm air mass off the ground and over another air mass.

8. 7 • Describe the storms that form along a cold front. • They are usually short-lived and sometimes violent. • A long line of heavy thunderstorms , called a squall line, may occur in the warm, moist air just ahead of a fast moving cold front.

9. 8 • What kind of weather does a warm front generally produce? • It produces precipitation over a large area and may cause violent weather.

10. 9 • The boundary where cold polar air meets the tropical air mass of the middle latitudes, especially over the ocean, is called the ________. • polar front

11. 10 • Bends that form in a stationary or cold fronts that are the beginnings of low-pressure storm centers are called _____. • waves

12. 11 • Also known as midlatitude cyclones, _______ are low-pressure storm centers. • wave cyclones

13. 12 • An area of low pressure that is characterized by rotating wind that moves toward the rising air of the central low-pressure region is called a _________ ______. • midlatitude cyclone.

14. 13 • Unlike the air in a midlatitude cyclone, the air of a(n) _________ sinks and flows outward from a center of high pressure. • anticyclone

15. 14 • Describe an anticyclone. • The air of a anticyclone sinks and flows outward from a center of high pressure. • Because of the Coriolis effect, the circulation of air is clockwise in the Northern Hemisphere.

16. 15 • What kind of weather does an anticyclone Bring? • Dry weather • If it stagnates for a few days it causes air pollution problems • If it lingers for a few weeks, it may cause droughts.

17. 16 • List three weather events that are considered severe weather. • Large amounts of rain • Lightning • Hail • Strong winds • Tornadoes

18. 17 • Thunderstorms: • A usually brief, heavy storm that consists of rain, strong winds, lightning, and thunder.

19. 18 • Lightning: • Electricity that is discharged during a thunderstorm.

20. 20 • Mature stage: • The second stage of a thunderstorm, in which condensation continues as the cloud rises and becomes a dark cumulonimbus cloud, perhaps producing torrential rain and hail.

21. 21 • Dissipating stage: • The third stage of a thunderstorm, in which strong downdrafts stop air currents from rising and the storm dies out as water vapor deceases.

22. 22 • Cumulus stage: • The first stage of a thunderstorm in which warm, moist air rises and water vapor in the air condenses to form a cumulus cloud.

23. 23 • Thunder: • An effect created when electricity heats the air, and the air expands rapidly.

24. 24 • A severe storm that develops over tropical oceans and whose winds of more than 120 km/h or 74.56 mph spiral in toward the intensely low-pressure storm center is called a(n) ________. • hurricane.

25. 25 • During a hurricane, large amounts of ____ ____ are released, increasing the force of the rising air. • latent heat

26. 26 • A fully developed hurricane consists of a series of thick ______________________ that spiral upward around the center of the storm. • cumulonimbus cloud bands

27. 27 • Winds increase toward the calm, clear ___ of the storm and may reach speeds of 275 km/h or 170.88 mph. • eye

28. 28 • The most dangerous aspect of a hurricane is a rising sea level and large waves, called a __________. • storm surge.

29. 29 • Every hurricane is categorized on the ________________. • Safir-Simpson scale.

30. 30 • Define tornado: • A tornado is a destructive, rotating column of air that has very high wind speeds and that may be visible as a funnel-shaped cloud.

31. The End