Chapter 12 - Tropical Storms Flashcards
Which region has the greatest incidence of major tropical storms?
The western North Pacific has the highest frequency of tropical cyclones (16.5 per year).
When are hurricanes most likely to form?
June to October in North America.
June to December in Asia.
January to March in Australia & east Africa.
What is the ‘trade wind inversion’?
A temperature inversion (layer of air with increasing temperature with altitude) commonly found at sub-tropical & tropical latitudes.
The great height of the inversion to the west allows for more convection and the formation of deep cumulus clouds. Thus hurricanes are more likely to form, especially in western portion of Ocean basins.
Describe cloud & precipitation patterns associated with hurricanes:
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How are hurricanes different from mid-latitude cyclones?
Hurricanes are smaller than mid-latitude cyclones.
How are Tropical Disturbances influenced by easterly waves?
Most Tropical Disturbances that enter the western Atlantic and become Hurricanes originate in ‘easterly waves’, which are large undulations or ripples in the normal trade wind pattern.
Describe ‘Tropical Disturbances’.
Tropical Disturbances are small clusters of thunderstorms. Hurricanes generally begin as Tropical Disturbances. (Stage 1 of Hurricane development)
Describe ‘Tropical Depressions’.
When Tropical Disturbances intensify into a rotating band of cloud cover and thunderstorm activity, they are considered Tropical Depressions. (Stage 2 of Hurricane development)
Describe ‘Tropical Storms’.
An intensified Tropical Depression can become a Tropical Storm if the wind speeds maintain above 39 miles per hour. At this point, the storm is named. (Stage 3 of Hurricane development)
Describe ‘Hurricanes’.
When a Tropical Storm continues to intensify and maintains wind speeds of 74 miles per hour, it is considered a true hurricane.
What ocean surface characteristics are required for the intensification of storms into hurricanes?
Oceans must have high surface temperatures in order to intensify & maintain a tropical storm or hurricane.
Is there a ‘typical’ path that hurricanes take after forming?
Hurricanes originate in tropical regions and migrate into the middle latitudes.
What feature associated with hurricanes causes the greatest destruction to coastal regions? Is this also true of inland regions?
The most serious threat posed by hurricanes is a ‘storm surge’. A storm surge is the elevated rise in sea level due to low atmospheric pressure and the piling up of water by strong winds. When occurring with a high tide, the storm surge’s flood water can penetrate considerable distances inland.
Where are tornadoes most likely to be embedded in a hurricane?
Tornadoes most likely form in the right-front quadrant of a hurricane.
What are hurricane watches & warnings? Are they exact corollaries to tornado watches & warnings?
A hurricane watch indicates that a hurricane is possible.
A hurricane warning indicates that a hurricane is expected.
