GLY 1001 Earth Science Sample Pretest Name:__Answers__

Chapter 19 Part K: Key Terms

Fill in the blanks with the word(s) that best fit the description:

1. hurricane - a tropical cyclonic storm having winds in excess of 119 kilometers (74 miles) per hour.

2. tornado - a small very intense cyclonic storm with exceedingly high winds, most often produced along cold fronts in conjunction with severe thunderstorms.

3. thunderstorm - a storm produced by a cumulonimbus cloud and always accompanied by lightning and thunder. It is of relatively short duration and usually accompanied by strong wind gusts, heavy rain, and sometimes hail.

4. air-mass - a large body of air that is characterized by a sameness of temperature humidity.

5. Polar (P) air mass - a cold air mass that forms in a high latitude source region.

6. Maritime (m) air mass - an air mass that originates over the ocean. These air masses are relatively humid.

7. Continental (c) air mass - an air mass which forms over land; it is normally relatively dry.

8. tropical (T) air mass - a warm air mass that forms in a low latitude source region.

9. air-mass weather - the conditions experienced in an area as an air mass passes over it. Because these are large and fairly homogeneous, This type of weather will be fairly constant and may last for several days.

10. Doppler Radar - in addition to the tasks performed by conventional radar, this new generation of weather radar can detect motion directly and hence greatly improve tornado and severe storm warnings.

11. front - the boundary between two adjoining air masses having contrasting characteristics.

12. warm front - a front along which a warm air mass overrides a retreating mass of cooler air.

13. cold front - a front along which a cold air mass thrusts beneath a warmer air mass.

14. occluded front - a front formed when a cloud front overtakes a warm front. it marks the beginning of the end of a middle latitude cyclone.

15. stationary front - a situation in which the surface position of a front doest not move; the flow on either side of such a boundary is nearly parallel to the position of the front.

16. overrunning - warm air gliding up a retreating air mass.

17. occlusion - the overtaking of one front by another.

18. eye - a zone of scattered clouds and calm averaging about 120 kilometers in diameter at the center of a hurricane.

19. tropical storm - by international agreement a tropical cyclone with maximum winds between 61 and 119 kilometers per hour.

20. eye wall - the doughnut-shaped area of intense cumulonimbus development and very strong winds that surrounds the eye of a hurricane.

21. tornado watch - a warning issued for areas of about 65,000 sq kilometers indicating that conditions are such that tornadoes may develop; it is intended to alert people to the possibility of tornadoes.

22. tornado warning - a warning issued when a tornado has actually been sighted in an area or is indicated by radar.

23. storm surge - the abnormal rise of the sea along a shore as a result of strong winds.

24. source region - the area where an air mass acquires its characteristic properties of temperature and moisture.

25. lake-effect snow - snow showers associated with a continental Polar cP air mass to which moisture and heat are added from below as the air mass traverses a large and relatively warm lake, rendering the air mass humid and unstable

26. middle-latitude cyclone - large center of low pressure with an associated cold front and often a warm front. Frequently accompanied by abundant precipitation.

Chapter 19 Word List:

air-mass air-mass weather cold front continental (c) air mass Doppler Radar eye eye wall front hurricane

lake-effect snow Maritime (m) air mass middle-latitude cyclone mid latitude cyclone occluded front occlusion overrunning Polar (P) air mass source region

stationary front storm surge thunderstorm tornado tornado warning tornado watch tropical (T) air mass tropical storm warm front