A Taiwan-bound flight from Hong Kong was forced to return to the airport yesterday after it was suspected to have been struck by lightning.
The Hong Kong Express Boeing 737, carrying 122 passengers, which left Hong Kong for Taichung at 12.30pm, landed safely back at Chek Lap Kok at about 2pm.
No one was hurt and the plane departed again soon after 4pm after checks found no damage.
It happened as thunderstorms swirled around the city, with the Observatory recording 683 lightning strikes in the hour from noon to 1pm and a total of 816 strikes from midnight to 8pm.
Thunder and heavy rain caused 200 flights to be delayed and six to be cancelled between 12.30pm and 5pm, the Airport Authority said.
Operations were back to normal in the evening.
Hong Kong Express said passengers on the delayed Flight UO162 stayed aboard the plane on the tarmac and were served a meal. No one complained of feeling unwell.
Former director of civil aviation Peter Lok Kung-nam said lightning strikes on planes usually posed no danger, but the aircraft would have had to return to check for cracks in the windscreen or damage to the navigation system's antenna.
Very rarely, a lightning strike could cause an electrical short in the fuel system, causing explosions.
A thunderstorm warning in force from 10am to 6pm was issued by the Observatory, which recorded 28.2mm of rain between midnight and 8pm.
More thunderstorms are expected in the next few days as a trough of low pressure brings rainy weather to the coastal areas of Guangdong.
Rain, heavy at times, is forecast for today with temperatures from 22 to 25 degrees Celsius. There will be fresh easterly winds, becoming moderate southerlies later. Rain will still be heavy at first on Saturday with thunderstorms.