Why was the flight from Shanghai to Shenzhen cancelled on September 5th?

On September 5th, the flight of Shanghai Airlines to Shenzhen was cancelled due to the influence of Typhoon "Xuanlannuo"1/. Specifically, China Eastern Airlines cancelled 78 flights in and out of Shanghai Pudong Airport before September 5 14, and will resume some flights after 14 depending on weather conditions. China Southern Airlines cancelled 42 inbound and outbound flights at Shanghai Hongqiao Airport and Pudong Airport on September 5th. In addition, airlines such as Spring Airlines, Jixiang and Jin Peng also cancelled some flights at Shanghai Pudong Airport on the 5th. Airlines are stepping up the monitoring of routes, airports and time slots affected by typhoons, releasing early warning information in time, and adjusting flight dynamic plans in time according to weather release standards.