Key for Homework 8

 

  1. Which has higher wind speeds--a tornado or a hurricane? Which generally inflicts more SEVERE damage--a tornado or a hurricane? Which kind of storm causes more WIDESPREAD damage?

    Tornadoes have higher winds, and therefore inflict more SEVERE damage. However, hurricanes are far larger and therefore inflict more WIDESPREAD damage.

  2. Why do hurricanes require cool, moist air in the middle troposphere? (Be sure to mention why the air should be cool, and why the air should be moist.)

    Hurricanes require COOL air aloft because if the air was warm, the atmosphere would be STABLE, which is bad for hurricane formation. Hurricanes need MOIST air aloft so that air that is entrained into the updrafts of the thunderstorms does not result in the evaporation of raindrops.

  3. Why do hurricanes require warm water at the surface? (This question has two parts: why must there be WATER at the surface, and why must it be WARM?)

    Hurricanes require WATER at the surface because they require enormous amounts of evaporation at the surface. The water must be WARM because the evaporation rate is greater over warm water than it is over cold water.

  4. About how many hurricanes and "named storms" occur in the North Atlantic every year? How about the South Atlantic?

    In the North Atlantic, there are about 9 named storms per year. In the South Atlantic, there are none.

  5. Give a typical pressure at the center of a hurricane, in millibars.

    950 mb

  6. Why do hurricanes require fairly unstable conditions?

    Hurricanes consist of hundreds of thunderstorms. Thunderstorms cannot exist in a stable environment.

  7. Which type of storm requires wind shear--a hurricane or a tornado?

    Tornado.

  8. What time of year is the peak of hurricane season in the North Atlantic?

    Autumn.

  9. What category was Hurricane Katrina at landfall?  What category was Hurricane Andrew at landfall?  (You might have to search on the web for this answer--if so, document your source.)  For each of the storms, tell me how great the winds were at landfall.

    Your answers for this will vary slightly, depending on the source of your information.  According to weather.unisys.com, Katrina was a Category 4 storm at landfall with winds of about 130 knots.  The same website reports that Andrew was also a Category 4 storm at landfall with winds of about 130 knots.