Impact of Typhoons Saola and Haikui Causes Record Rainfall in Hong Kong, Submerging Roads and Subway Stations.
Record rainfall in Hong Kong this weekend. (Video: HKFP).
Heavy rain began to fall in Hong Kong on the evening of September 7. From 11 PM until midnight, more than 158mm of rainfall was recorded, the highest level since 1884, according to the Hong Kong Observatory. This record amount of rain caused flooding, submerged subway stations, trapped drivers, and forced schools to close.
The extreme weather phenomenon in Hong Kong serves as a reminder that climate change is truly here, according to Lam Chiu-ying, former director of the Hong Kong Observatory. He remarked that the torrential rain causing severe flooding and landslides in many districts across Hong Kong was something “unimaginable” half a century ago.
The heavy rains were a result of the influence of two powerful typhoons, Saola and Haikui, according to extreme weather scientist Chu Jung-eun, a professor at City University of Hong Kong. Typhoon Saola made landfall in Hong Kong the weekend before, causing serious flooding, downed trees, and blown-off solar panels. The typhoon has moved away from Hong Kong but continues to indirectly affect the city due to the southwest monsoon flow.
Chu stated that air movements formed by Typhoons Saola and Haikui converged over Hong Kong on the evening of September 7, resulting in very localized heavy rainfall. She added that both typhoons rapidly intensified, with their strength increasing by more than 50 km/h within 24 hours.
According to climate simulations conducted by Chu and consensus views from experts in the field, typhoons will become stronger with more rainfall under the influence of climate change. “Climate change will undoubtedly affect typhoon intensity”, Chu stated. She further explained that typhoons also receive more energy from the warming ocean due to El Niño—a natural phenomenon that raises sea surface temperatures regardless of human activity.
Climate change will undoubtedly affect typhoon intensity.
The world has witnessed record-high ocean surface temperatures, including in the northern part of the South China Sea off the coast of Hong Kong, according to Professor Jed Kaplan at the University of Calgary, Canada. Warmer ocean temperatures lead to increased humidity in the air, which can create rainfall under suitable meteorological conditions.
Kaplan noted that Hong Kong is experiencing climate change, not only evident through tropical storms but also through extremely hot days and nights. “All these meteorological phenomena lead to challenging situations for humanity: increased cases of heat shock and heat-related illnesses, infrastructure damage due to floods, strong winds, and landslides, resulting in economic damage and costly investments in repairs and risk mitigation in the future”, he stated.
