11 terms

CH. 14 - Questions-Weather Patterns

What are the characteristics of a maritime tropical air mass? Where are the source regions for the maritime tropical air masses that affect North America? Where are the source regions for the maritime polar air masses?
2. A maritime tropical (mT) air mass is humid because it originates over water and warm because it forms in tropical latitudes. Source areas for mT air masses are the Gulf of Mexico, Caribbean and adjacent Atlantic Ocean, and the Pacific, west of Mexico. Maritime polar (mP) air masses originate in the orth Pacific and off the eastern coast of
Canada in the North Atlantic.
What is the primary requirement for the formation of thunderstorms?
7. Since thunderstorms are produced in towering cumulonimbus clouds, a prime requirement is warm, moist, unstable air.
Based on your answer to Q.7, where would you expect thunderstorms to be most common on Earth? Where specifically in the US?
8. In areas where warm, moist, and unstable air is very common; i.e., the tropics. In the U.S. thunderstorms would be most common during the summer months and likely most prevalent in the Southeast near the primary source of maritime tropical air.
Why do tornadoes have such high wind speeds?
9. Because of the very low pressure within the tornado there is a very steep pressure gradient and, hence, very high wind speeds.
What general atmospheric conditions are most conducive to the formation of tornadoes?
10. Tornadoes are most often spawned along the cold front of a mid-latitude cyclone in association with severe thunderstorms. During spring, the air masses on either side of the cold front are most likely to have greatly contrasting conditions.
When is "tornado season"? That is, during what months is tornado activity most pronounced?
11. Although tornadoes can occur in every month of the year, spring (April-June) is the period of greatest tornado activity.
Distinguish between a tornado watch and a tornado warning.
12. A tornado watch alerts the public to the fact that conditions are right for the formation of tornadoes. A tornado warning is issued when a tornado has actually been sighted in an area or is indicated by radar.
Which has stronger winds, a tropical storm or a tropical depression?
13. With wind speeds between 61 and 115 km per hour, a tropical storm has stronger winds than a tropical depression.
Why does the intensity of a hurricane diminish rapidly when it moves onto land?
14. The most important reason for this rapid demise is the fact that the storms source of warm, moist air is cut off. When an adequate supply of water vapor does not exist, condensation and the release of latent heat must diminish. In addition, because the land is usually cooler than the ocean, the low-level air is chilled rather than warmed. Moreover, the increased surface roughness over land results in a rapid reduction in surface wind speeds. This factor causes the winds to move more directly into the center of the low, thus helping to eliminate the large pressure differences.
Name the three broad categories of hurricane damage. Which category is responsible for the highest percentage of hurricane-related deaths.
15. The three broad categories of hurricane damage are: (1) wind damage, (2) storm surge, and (3) inland freshwater flooding. Storm surge is responsible for the greatest percentage
of hurricane-related deaths.
A hurricane has slower wind speeds than does a tornado, yet it inflicts more total damage. How might this be explained?
16. Since the hurricane is so much larger and lasts not for a fraction of an hour but for days, the destruction it causes is considerably greater than that caused by a tornado.