The Observatory issued its second-longest black signal on Tuesday, after warnings sent out at all hours in recent days.

Observatory warns residents to ‘be on the alert’ as thunderstorms developing in Pearl River Delta could affect the city ‘shortly’.

Though rainstorm warning has been cancelled, Observatory urges residents to ‘stay alert’ to dangers from river flooding.

The Hong Kong weather forecaster issued the black rainstorm signal at 5.50am this morning with the previous one raised at 11.45pm on Monday evening.

Forecaster issues highest-level storm warning at 5.50am, prompting authorities to suspend all morning and whole-day schools.

Forecaster issues highest-level storm warning at 5.50am, prompting authorities to suspend all morning and whole-day schools.

Forecaster issues highest-level storm warning at 5.50am, prompting authorities to suspend all morning and whole-day schools.

So far, 101 flights are delayed, two cancelled and two diverted to other airports.

Observatory cancels all rainstorm warnings after city brought to standstill, with over 100 flights delayed and public services paralysed.

The Observatory issued its second-longest black signal on Tuesday, after warnings sent out at all hours in recent days.

Highest daily rainfall in August on record causes flooding, landslides and disruption to public services.

Veteran meteorologist warns that global warming could mean more instances of extreme wet weather in Hong Kong are likely to occur in long run.