Wet, wet walk: The black rainstorm warning signal sent students scurrying home from schools.

The black rainstorm warning signal was issued after an active trough of low pressure brought unsettled weather to Hong Kong on Friday, closing afternoon schools.

Since midnight, the Hong Kong Observatory said most parts of the New Territories had recorded more than 100mm of rain. It issued the Amber Rainstorm Warning Signal at 10.25am, the red signal at 10.55am and the black warning at 11.15am. The rainstorm signal was lowered to amber at 2.20pm and then cancelled an hour later, while the landslip warning was issued at 2.30pm.

Flood alert

A flood alert for the New Territories was issued at 10.40am, as heavy rain affected northern areas, especially in Yuen Long, which has seen more than 70mm in the past 24 hours. The alert was cancelled at 4pm.

The bad weather closed classes for all schools, skills centres for the disabled, the Institute of Vocational Education, the Vocational Training Council School of Business & Information Systems, the Youth College and all training and development centres.

All courts, tribunals, court registries and offices were also closed. However, all childcare centres, elderly services centres and day rehabilitation units, including sheltered workshops and day activity centres, remain open.

Shelters open

The Home Affairs Department's Emergency Co-ordination Centre is in operation, and temporary shelters have been opened for people in need of accommodation. Enquiries can be made on 2835 1473.

The observatory forecasts occasional heavy rain and squally thunderstorms for this afternoon and tonight. There will be moderate southwesterly winds, gusty at times. Occasional heavy rain is expected tomorrow, and the weather for early next week is forecast to be showery.