This story has been made freely available as a public service to our readers. Please consider supporting SCMP’s journalism by subscribing.Hong Kong is bracing for a series of thunderstorms on the weekend, with the weather forecaster issuing an amber rainstorm warning on Saturday morning.The Hong Kong Observatory announced the amber warning, the lowest of the three-tiered rainstorm warning system, at 11am. It also said rain was particularly heavy in Tai Po district and might cause serious...