CHAPTER 10 WEATHER SYSTEMS OF MIDDLE LATITUDES __________________________________________________________ MULTIPLE CHOICE QUESTIONS 1. a. b. c. d. e. In equal volumes, which one of the following air masses exerts the highest surface air pressure? cP A mP cT mT 2. a. b. c. In summer, at the same pressure, maritime tropical air is ______ continental tropical air. more dense than as dense as less dense than 3. a. b. c. d. e. A source region for maritime tropical air is northern Canada. American Southwest. the Gulf of Mexico. the North Atlantic. None of these is correct. 4. a. b. c. d. e. Warm and humid air: A mP mT cP cT 5. a. b. c. d. e. At the same pressure, which one of the following air masses is least dense? maritime tropical arctic maritime polar continental tropical continental polar 6. a. b. c. d. At the same pressure, which one of the following air masses is most dense in winter? maritime tropical arctic maritime polar continental tropical e. continental polar 7. Of the following air masses, which one exhibits the greatest temperature change between winter and summer? a. maritime tropical b. continental polar c. maritime polar d. equatorial 8. a. b. c. d. Usually air mass modification is most rapid when continental polar air moves over a frozen lake. continental polar air travels over a snow-covered ground. continental polar air moves over bare ground. maritime tropical air moves over bare ground. 9. a. b. c. In winter, continental polar air is ______ maritime polar air. colder than warmer than about the same temperature as 10. As warm front approaches, clouds appear in which one of the following sequences? a. cirrus, altostratus, stratus b. stratus, altostratus, cirrus c. cumulus, cumulonimbus, cirrus d. cumulonimbus, cumulus, nimbostratus e. nimbostratus, cirrocumulus, cirrus 11. A cloud that indicates warm air advection aloft: a. cumulus b. cirrus c. stratus d. None of these is correct. 12. The cloud and precipitation shield associated with a cold front typically is ______ the cloud and precipitation shield associated with a warm front. a. wider than b. narrower than c. the same width as 13. A front is a narrow zone of transition between air masses that contrast in a. temperature. b. vapor pressure. c. density. d. Any of these is correct. e. None of these is correct. 14. A type of cloud associated with a fast-moving, well-defined cold front: a. cirrus b. stratus c. cumulonimbus d. cirrostratus e. None of these is correct. 15. Cold fronts typically travel ______ warm fronts. a. faster than b. slower than c. at the same speed as 16. The type of front formed when the leading edge of cold air merges with a warm front is known as a. a cold front. b. a warm front. c. a stationary front. d. an occluded front. e. None of these is correct. 17. An occluded front forms a. during the early stages in the life cycle of a wave cyclone. b. just as a cyclone approaches maturity. c. late in the life cycle of an extratropical cyclone. d. near the center of an anticyclone. e. None of the above is correct. 18. If the surface wind backs from northeast to north, Boston usually experiences a. cold air advection. b. warm air advection. c. snow changing to rain. d. falling air pressure. e. hail. 19. If the surface wind veers from east to southeast to south, Baltimore usually experiences a. cold air advection. b. warm air advection. c. rain changing to snow. d. rising air pressure. e. falling temperatures. 20. In a mature extratropical cyclone, fog and drizzle are most likely to develop a. to the northwest of the low center. b. in the warm air behind the warm front. c. in the cold air just ahead of the surface warm front. d. in the warm air just ahead of the surface cold front. e. None of the above is correct. 21. If a weather station reports a wind shift from northeast to north and then northwest and a steady rain turning to snow flurries, the low center is most likely moving a. from west to east, north of the station. b. from northeast to southwest, north of the station. c. from southwest to northeast, east of the station. d. from southwest to northeast, north of the station. e. None of the above is correct. 22. Contrasting air masses are brought together to form fronts by the surface winds about centers of ______ pressure. a. low b. high 23. Surface air pressure drops when horizontal divergence aloft ______ horizontal convergence at the surface. a. balances b. is greater than c. is less than 24. A surface wind that backs with time indicates that you are situated on the ______ side of the track of an extratropical cyclone. a. cold b. warm 25. Precipitation tends to be steady and persistent in the ______ sector of a mature extratropical cyclone. a. northeast b. northwest c. southeast d. southwest 26. The coldest sector of a mature extratropical cyclone is usually __________ of the cyclone center. a. northeast b. northwest c. southeast d. southwest 27. The warmest sector of a mature extratropical cyclone is usually __________ of the cyclone center. a. northeast b. northwest c. southeast d. southwest 28. The warmest air associated with a mature extratropical cyclone is usually located a. at the low center. b. southwest of the low center. c. northwest of the low center. d. southeast of the low center. e. None of the above is correct. 29. What is the surface wind direction in the northwest sector of a mature extratropical cyclone? a. southeast b. east c. south d. northwest e. southwest 30. Major winter storms that most directly affect central Indiana follow the ______ cyclone track. a. Alberta b. Colorado c. Atlantic coast d. Gulf e. Cape Hatteras 31. In the southwestern United States, heat (thermal) lows generally a. remain stationary. b. drift slowly westward. c. are very cold. d. track toward New England. e. move southeastward. 32. An intense extratropical cyclone tracks up the Mississippi River Valley and passes well west of Chicago. As the cold front sweeps through Chicago, the wind shifts from the south to the a. southeast. b. southwest. 33. An example of a cold-core anticyclone is the a. Hawaiian high. b. Bermuda-Azores high. c. Siberian high. d. Pacific high. e. Aleutian low. 34. At the center of a polar high, the horizontal pressure gradient is weak and winds are a. strong. b. moderate. c. light or calm. 35. Nocturnal radiational cooling is most intense a. at the center of an anticyclone. b. to the east of the center of a high. c. to the west of the center of a high. d. to the south of the center of a high. e. to the north of the center of a high. 36. Warm air advection takes place to the ______ of a ridge and to the ______ of a trough. a. west...............east b. east...............west 37. The relatively warm side of a cyclone track: a. to the right of the system's forward motion b. to the left of the system's forward motion 38. Cyclones that occur with the greatest frequency over North America: a. Colorado b. South Pacific c. Panhandle d. East Gulf e. Alberta 39. Viewed from above, the surface wind circulation about an Alberta-type cyclone is a. clockwise and outward. b. clockwise and inward. c. counterclockwise and outward. d. counterclockwise and inward. e. None of the above is correct. 40. The most common type of occlusion in the Great Lakes region is the a. warm-type occlusion. b. Cape Hatteras occlusion. c. cold-type occlusion. d. Alberta-type occlusion. e. Panhandle hook occlusion. 41. When land and water are exposed to the same intensity of solar radiation, the land heats up ______ the water. a. more than b. less than c. about the same as 42. At night, radiational cooling chills a land surface ______ a water surface. a. less than b. more than c. about the same as 43. The time of day when a summer sea breeze is likely to be strongest is a. midnight. b. 6 a.m. c. noon. d. 2 p.m. e. 10 p.m. 44. During a lake breeze, the horizontal pressure gradient force is directed a. parallel to the coastline. b. perpendicular to the coastline from lake to land. c. perpendicular to the coastline from land to lake. 45. The time of year when a lake breeze is most likely to develop along the Lake Michigan shoreline is a. February. b. June. c. late autumn. d. December. e. November. 46. The chinook wind blows down the leeward slopes of mountain ranges and is characteristically a. cold and dry. b. warm and dry. c. cold and humid. d. warm and humid. 47. Chinook winds a. warm at the moist adiabatic rate. b. flow downhill under the influence of gravity. c. occur only on the windward slopes of a mountain range. d. All of the above are correct. e. None of the above is correct. 48. As a chinook wind is drawn down the leeward slopes of a mountain range a. the air temperature rises. b. the saturation vapor pressure increases. c. the relative humidity decreases. d. All of the above are correct. e. None of the above is correct. 49. A dust devil a. may resemble a small tornado. b. is not linked to a cloud. c. typically causes little or no property damage. d. All of these are correct. e. None of these is correct. 50. A mountain breeze blows a. upslope at night. b. upslope during the day. c. downslope at night. d. downslope during the day.