MSCI Lab 4 Hurricanes

What direction does wind move in atmospheric circulation?

From high pressure (cool, sinking air) to low pressure (warm, rising air), creating wind.

Q2: What are the dates of the Atlantic hurricane season?

June 1 – November 30.

Q3: What are the two main conditions required for hurricane development?

1. Warm ocean water (surface >26°C / 79°F).

2. Rotational force from the Coriolis Effect.

Q4: What provides the rotation necessary for hurricane formation?

The Coriolis Effect.

Q5: In which direction does the Coriolis Effect deflect moving objects in the Northern Hemisphere?

A5: To the right.

Q6: In which direction does the Coriolis Effect deflect moving objects in the Southern Hemisphere?

to the left

Q7: Why is there no Coriolis Effect at the equator?

A7: Because the rotational speed doesn't change across latitude at the equator.

Q8: What is the direction of rotation for hurricanes in the Northern Hemisphere?

A8: Counterclockwise (due to Coriolis deflection to the right).

Q9: What is the direction of rotation for hurricanes in the Southern Hemisphere?

A9: Clockwise (due to Coriolis deflection to the left).

Q10: What is the difference between a hurricane, typhoon, and cyclone?

• Names are based on location but all are storm systems over warm water and have low pressure centers

• Hurricane – Atlantic Ocean

• Typhoon – Western Pacific

• Cyclone – Indian Ocean

Q11: What are the three main parts of a hurricane?

• Eye – calm, lowest pressure

• Eyewall – strongest winds, heaviest rain

• Spiral rain bands – windy, rainy outer bands

Q12: How do you calculate actual wind speed in a hurricane?

• If steering and storm winds are in the same direction: add

• If opposite directions: subtract

• If not aligned: use sustained wind speed only

Q13: What is the worst (strongest) side of a hurricane in the Northern Hemisphere?

The right front quadrant (strongest winds, storm surge, tornado risk).

Q14: How do you read a wind barb showing 115 knots from the NE?

• 50 + 50 + 10 + 5 = 115 kt

• Wind is blowing to the SW, from the NE

Q15: At what wind speed does a tropical storm become a hurricane?

When sustained winds reach 74 mph.

Q16: What scale is used to classify hurricane strength?

 The Saffir-Simpson Hurricane Wind Scale (Category 1–5 based on wind speed).

Q17: What are the 4 main hazards of hurricanes?

1. Strong winds

2. Heavy rain (flooding)

3. Tornadoes & lightning

4. Storm surge

Q18: What causes storm surge?

• High winds push ocean water onto land

• Low pressure allows sea level to rise
  Biggest threat to life during hurricanes

Q19: What was the deadliest natural disaster in U.S. history?

The Great Galveston Hurricane (1900) – ~8,000 deaths, no warning system.

Q20: What happens if a pilot from South Carolina to Arizona forgets to adjust for the Coriolis Effect?

The plane ends up too far north.