Coastal Hazards - Tropical Storms

Question 1

What are tropical storms?

Answer 1

• rotating warm humid air mass
• form in the tropics
• Strong winds and torrential rain
• Low P centre
• Sustained winds above 119 km/hr

Question 2

What are the three types of tropical storms?

Answer 2

• Cyclones: indian and south pacific
• Hurricanes: atlantic & North-eastern Pacific, Gulf of Mexico, Caribbean Sea
• Typhoons: North-western Pacific

Question 3

explain the different hurrincane rotations?

Answer 3

• Southern Hemisphere: Clockwise
• Northern Hemisphere: Counterclockwise

Question 4

Why do storms rotate?

Answer 4

• Coriolis effect
• Air movement towards low P centre

Question 5

What are the origins of hurricanes?

Answer 5

Form at low latitudes
- in summer months

Question 6

How do hurricanes form?

Answer 6

• As air cools, water condenses creating rain - releases energy (latent heat) that powers the storm
• Latent heat of condensation
• Warm, moist air continues to rush in (feeding the storm and getting larger)

Question 7

Explain Hurricane Anatomy?

Answer 7

• Eye: calm winds, no precipitation
• Eye wall: strongest surface winds
• Rain bands: long narrow bands of rain and thunderstorms

Question 8

What are the hurricane hazards?

Answer 8

• Heavy rainfall and flooding
• High winds
• Tornadoes
• Storm surge

Question 9

What is the Saffir-Simpson Hurricane Wind Scale

Answer 9

ranges from category 1-5 and tells the amount of damage that will occur from storm wind speeds

Question 10

How are tornadoes triggered?

Answer 10

Hurricanes that make landfall can cause tornadoes

Question 11

What is the “Storm surge”?

Answer 11

• The most hazardous part of a hurricane
• Local abnormal and rapid rise in sea level coastal flooding
• Combination of wind and pressure pushing water onshore

Question 12

How does Storm Surge occur?

Answer 12

• water pushed towards shore by wind moving cyclonically around the storm

Question 13

What does the Storm Surge depend on?

Answer 13

• Hurricane size and intensity
• How fast hurricane is moving
• Coastline configuration
• Slope of seabed
• High or low tide

Question 14

Explain hazards of Storm surge?

Answer 14

Hurricane makes landfall and has nowhere to go but inland
- Extreme coastal flooding when surge coincides with high tide
- Coastal erosion
- Damaged buildings and infrastructure

Question 15

How does Sea bed affect storm surge?

Answer 15

• seabed with gentler slope will make the Storm surge worse
• Seabed with steeper slope will lessen the effects of storm surge

Question 16

Describe Hurricane Fiona?

Answer 16

• Cat 3-4
• Costliest and most intense tropical storm to hit Canada
• Was post-tropical due to category 1 winds

Question 17

what was the costliest weather disaster?

Answer 17

Hurricane Ian ($40 Billion)

Question 18

Are hurricane storms becoming more frequent with warming oceans?

Answer 18

No,
- But more category 4-6 storms

Question 19

What is Rapid Intensification?

Answer 19

Increase in the maximum sustained to at least 56mph in a 24 hour period

Question 20

what is required for rapid intensification?

Answer 20

• Moist air
• Warm ocean water
• Low wind shear