The Hong Kong Observatory issued an amber rainstorm warning on Saturday morning as thundery showers and strong gusts swept across the city, following the hottest day of the year so far. The amber alert, the lowest in a three-tier rainstorm warning system, was issued at 10am. It indicates that more than 30mm (1.2 inches) of rain has fallen or is expected to fall within an hour across Hong Kong. “A broad trough of low pressure is bringing showers and thunderstorms to the coast of Guangdong,” the..