SCI261 - topic 6 (hurricanes)

In which direction do hurricanes rotate in the Northern Hemisphere?

• counterclockwise and inward coiling pattern into L

• clockwise and outward diverging flow away from H

In which direction do hurricanes rotate in the Southern Hemisphere?

• clockwise and inward coiling pattern into L

• counterclockwise and outward diverging flow away from H

Why is the core/eye of a hurricane clear and cloud-free?

Inside, the hurricane’s air mass air descends, warms adiabatically and clouds evaporate

Where are the strongest winds in a hurricane?

the eyewall

What is the relationship between the category of a hurricane on the Saffir-Simpson Scale, barometric pressure, and wind speed?

As hurricane category (1-5) increases:
→ Wind speed increases
→ Barometric pressure decreases

What are the factors that influence the path of a tropical cyclone?

•Sea surface temperature of at least 80°F

•Low pressure systems → Rotation in the atmosphere

•Cannot have wind shear

•Lack of wind shear

What conditions lead to a prediction for a greater number of named storms in the Atlantic Ocean?

•Wet conditions in Sahel of Africa

•Warm sea-surface temperatures

•Low atmospheric pressure in Caribbean

•La Niña conditions in Pacific à west blowing trade winds help move developing hurricanes over warm water

What are most deaths related to tropical cyclones the result of?

sea surges

In the Northern Hemisphere, in which region of the hurricane is the storm surge the most extreme due to the forward motion of the storm motion and the direction of rotating winds?

right front quadrant

What is the evacuation dilemma in regard to hurricanes?

There are often more people living in coastal cites than can be safely evacuated in less than 72 hours, potentially trapping them in traffic jams when the storm hits.

In which quadrant of a hurricane is the storm surge the greatest?

right front

Has the number of hurricane deaths in the United States increased or decreased in the latter part of the 20^thcentury?

decreased