Typhoon Wipha's Wrath: Strong Winds, Heavy Rainfall, and Flight Cancellations in Hong Kong

Why in News?

• On 20th July, Hong Kong issued its most severe warning for Typhoon Wipha.
• Wind speeds exceeded 167 km/h.

Key Points:

• Over 400 flights disrupted and more than 200 flights canceled due to Typhoon Wipha.
• The storm passed south of the Hong Kong Observatory, with the southern districts being most affected.
• Cathay Pacific canceled all flights considering passenger safety.
• In North Point, a scaffold collapsed and a construction site was damaged.
• The storm is moving towards China’s Guangdong province, and warning levels were lowered in Macau.
• Over 80,000 passengers affected, with public transport and ferry services suspended.

What is a Tropical Storm?

• A tropical storm is a type of rapidly rotating cyclone that originates over tropical oceans.
• It has a low-pressure center with clouds rotating around it.

Intensity and Impact of Tropical Storms:

• The intensity is based on wind speed.
• When the maximum sustained wind speed of a tropical cyclone is between 34 knots (63 km/h) and 47 knots (87 km/h), it is classified as a tropical storm.
• Such storms can bring torrential rain, strong winds, high sea waves, coastal flooding, and landslides.
• Winds rotate anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

Regional Names of Tropical Storms:

Depending on the geographic region, tropical storms are known by different names:

• Northern Atlantic: Hurricane
• Western North Pacific: Typhoon
• Indian Ocean & South Pacific Ocean: Tropical Cyclone

Formation Conditions for Tropical Cyclones:

Tropical cyclones form under the following favorable conditions:

• Warm ocean waters [typically 26–27°C (79–81°F)]
• Sufficient moisture in the atmosphere
• Low to moderate wind shear (variation in wind speed/direction)
• Coriolis force (caused by Earth’s rotation)