Tropical Cyclone Classification

Cyclone Classification

Tropical Cyclone Classification Scales

• Saffir-Simpson Hurricane Wind Scale
  • Classifies hurricanes based on wind speed
  • Categories 1-5, with 5 being the highest
• Tropical Cyclone Intensity Scale
  • Used in the Western Pacific Ocean
  • Classifies typhoons into 5 categories (T1-T5)
  • Based on wind speed and central pressure
• India Meteorological Department (IMD) Scale
  • Used in the North Indian Ocean
  • Classifies cyclones into 5 categories (Low Pressure Area to Super Cyclonic Storm)
  • Based on wind speed and central pressure

Classification by Wind Speed

• Tropical Depression
  • Wind speed: 38 mph (33 knots) or less
• Tropical Storm
  • Wind speed: 39-73 mph (34-63 knots)
• Typhoon
  • Wind speed: 74 mph (64 knots) or higher
• Super Typhoon
  • Wind speed: 150 mph (130 knots) or higher

Classification by Central Pressure

• Tropical Cyclone
  • Central pressure: 980 hPa or lower
• Severe Tropical Cyclone
  • Central pressure: 930 hPa or lower

Cyclone Classification

Tropical Cyclone Classification Scales

• Saffir-Simpson Hurricane Wind Scale categorizes hurricanes into 5 categories based on wind speed, with Category 5 being the highest.
• Tropical Cyclone Intensity Scale, used in the Western Pacific Ocean, classifies typhoons into 5 categories (T1-T5) based on wind speed and central pressure.
• India Meteorological Department (IMD) Scale, used in the North Indian Ocean, classifies cyclones into 5 categories (Low Pressure Area to Super Cyclonic Storm) based on wind speed and central pressure.

Classification by Wind Speed

• Tropical Depression has a wind speed of 38 mph (33 knots) or less.
• Tropical Storm has a wind speed of 39-73 mph (34-63 knots).
• Typhoon has a wind speed of 74 mph (64 knots) or higher.
• Super Typhoon has a wind speed of 150 mph (130 knots) or higher.

Classification by Central Pressure

• Tropical Cyclone has a central pressure of 980 hPa or lower.
• Severe Tropical Cyclone has a central pressure of 930 hPa or lower.

Definition and Formation

• Occurs in the Northwestern Pacific Ocean, specifically in the western Pacific Ocean.
• Formed when a low-pressure system strengthens over warm ocean waters (at least 26.5°C) in the tropics.
• Warm ocean waters heat the air above, causing it to rise and create low pressure, which fuels the storm.

Characteristics

• Have strong winds of at least 119 km/h (74 mph).
• Bring heavy rainfall, leading to flooding and landslides.
• Cause storm surge, a rise in sea level, resulting in coastal flooding.

Classification

• Classified based on wind speed into four categories: Tropical Depression, Tropical Storm, Typhoon, and Super Typhoon.
• Tropical Depression: wind speed < 38 mph (61 km/h).
• Tropical Storm: wind speed of 39-73 mph (63-118 km/h).
• Typhoon: wind speed of 74-119 mph (119-191 km/h).
• Super Typhoon: wind speed of 120 mph (193 km/h) or higher.

Life Cycle

• Form over warm ocean waters in the tropics.
• Reach peak intensity during maturity.
• Weaken and eventually dissipate during dissipation.

Impact

• Cause extensive damage to infrastructure, agriculture, and human life.
• Lead to flooding and landslides.
• Storm surge causes coastal erosion and saltwater intrusion into freshwater sources.