Troical Revolving Stroms (TRS)

Question 1

Where do tropical revolving storms usually develop?

Answer 1

At or Near the Inter-Tropical Convergence Zone (ITCZ)

Question 2

What are the conditions for a TRS to develop? Explain why.

Answer 2

• Sea Temperature not less than 27C:
  A TRS is driven by warm, moist air.
• Enough Coriolis effect:
  To enable the system to start rotating.
• Pre-Existing Cloud System:
  A TRS is a group of pre-existing cloud systems.
• Limited Wind Shear:
  Because the wind shear will knock it down before a rotating system starts
• Airflow Divergence

Question 3

What are TRSs called in different regions?

Answer 3

Atlantic and North-Eastern Pacific:
Hurricanes

North-Western Pacific:
Typhoons

South Pacific & Indian Ocean:
Cyclones

Question 4

What is a tropical storms?

Answer 4

Intense and rapidly rotating depressions that develop in tropical latitudes.

Question 5

Signs of a tropical storm?

Answer 5

• A Long Low Swell
• Diurnal Variation is Suppressed
• Fall of Pressure less than 3 mb below the mean for that area and time of year as per Admiralty Sailing Directions. A FALL OF 5MB IS ABSOLUTE CONFIRMATION.
• An appreciable change in direction of wind or strength of wind.
• Extensive Cirrus Clouds & Excellent Visibility

Question 6

At what speed and Beaufort scale is a hurricane declared?

Answer 6

At 64 Knots, Force 12.

Question 7

Determine your position inside a TRS.

Answer 7

Wind Direction - Speed - Pressure
- Veering - Increasing - Falling: Adv Right
- Backing - Increasing - Falling: Adv Left
- Steady - Increasing - Falling: On Path
- Veering - Decreasing - Rising: Rear Right
- Backing - Decreasing - Rising: Rear Left

Question 8

Inside a TRS what does it mean if the wind is:
- Veering
- Backing
- Increasing
- Decreasing

Answer 8

Veering - We’re on the right
Backing - We’re on the left
Increasing - We’re ahead
Decreasing - We’re in the Rear

Question 9

Why is the dangerous quadrant in a TRS called so?

Answer 9

• The storm will likely recurve that way
• The Wind and Waves push the vessel back into the path of the storm.
• The wind speed is higher

Question 10

Where is the dangerously quarter in a TRS in Northern and southern Hemisphere?

Answer 10

Northern - Advance Right
Southern - Advance Left

Question 11

Action to Avoid TRS in Northern Hemisphere:
- Dangerous Quadrant
- Navigable Semicircle

Answer 11

Dangerous Quadrant:
- Place wind on Stbd Bow and make best speed
- Alter Course to Stbd as wind veers

Navigable Semicircle:
- Place wind on Stbd Quarter and make best speed
- Alter Course to Port as wind backs

Question 12

Action to Avoid TRS in Southern Hemisphere:
- Dangerous Quadrant
- Navigable Semicircle

Answer 12

Dangerous Quadrant:
- Place wind on Port Bow and make best speed
- Alter Course to Port as wind backs

Navigable Semicircle:
- Place wind on Port Quarter and make best speed
- Alter Course to Stbd as wind veers