HONG KONG – Flooding left hikers trapped and roads overflooded, disrupting traffic, in some parts of Hong Kong as the city’s weather forecaster issued the first red rainstorm signal of the year on Saturday.

The Hong Kong Observatory raised the possibility in the morning of upgrading the signal to black with intense thundery showers gradually moving eastwards to the city while heavy downpours forced the closure of schools.

The eastern part of the city was most affected by the rainfall with over 200 millimeters of rain falling in Sai Kung and Tseung Kwan O, according to the observatory.

The transport authorities closed seven roads in Sai Kung district and part of the Tseung Kwan O – Lam Tin Tunnel.

READ MORE: Rain batters HK as HKO issues amber rainstorm warning

Local media reported that hundreds of private vehicles were left submerged in water after due to flooding of a large public car park near Lohas Park. Some motorists there were forced to hire tow trucks to retrieve their vehicles.

Many cars were damaged there, District Councilor Christine Fong told RTHK. “For that particular outdoor car park area, there are around 450 cars. I think half of the cars were seriously (flooded).”

The Education Bureau announced on Saturday morning that afternoon classes in all schools have been canceled following the hoisting of the red rainstorm signal

Kowloon Motor Bus said bus services to Tseung Kwan O and surrounding areas have been affected by severe weather. with Routes 33R, 63R, 74R, 94, 96R and 289R already suspended for the whole day.

Route 91 temporarily terminates at the Hong Kong University of Science and Technology until further notice, KMB said.

Police rescued two groups of hikers who were stranded near Sai Kung. A group of 11 Chinese mainland tourists including seven children, who were camping in the area, contacted police at about 11:30 am, after finding themselves stranded at High Island Reservoir East Dam, according to local media.

Rescuers received calls from four local hikers around the same time from section two of the MacLehose Trail.

Officers were able to locate all of the stranded hikers and evacuate them.

Red rainstorm signal

The observatory first issued the amber rainstorm warning at 7:40 am and upgraded it to red at 8:55 am as the situation worsened. A red rainstorm warning means rainfall exceeding 50 millimeters has fallen in an hour and is likely to continue.

In an 11:45 am notification, the HKO said an area of intense thundery showers over the Pearl River Estuary was gradually moving eastwards. It warned that it might issue the black rainstorm warning signal if it continued to edge closer to Hong Kong with same intensity.

However, the forecaster lowered the rainstorm warning signal to amber at 3:50 pm, meaning that heavy rain has fallen or is expected to fall generally over Hong Kong, exceeding 30 mm in an hour, and is likely to continue.

“The band of intense thundery showers to the west of the Pearl River Estuary is edging towards Hong Kong,” the HKO said in an alert at 5:05 pm, warning that there will be heavy showers, thunderstorms and intense gusts shortly.

In the morning, it asked people to stay away from watercourses across the city due to the possibility of flash floods, warning that severe rainstorms would continue to affect the eastern part of Hong Kong.

“Residents living in close proximity to rivers should stay alert to weather conditions and should consider evacuation if their homes may become flooded,” the HKO said in an 8:55 am bulletin.

At 10:30 am, it issued landslip warning, asking people to keep away from steep slopes or retaining walls. “Motorists should avoid driving in hilly areas or on roads with landslip signs,” it said.

A thunderstorm warning issued at 5:00 am has been extended until 8:30 pm.

A few squally thunderstorms are expected to occur over Hong Kong, the observatory said, warning that intense gusts reaching 70 kilometers per hour or above may affect the city.

Class suspension

The Education Bureau announced on Saturday morning that afternoon classes in all schools have been canceled following the hoisting of the red rainstorm signal.

Schools having morning classes must ensure the safety of students before allowing them to return home, the bureau said.

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The Mona Fong General Out-patient Clinic in Sai Kung and the Tseung Kwan O Jockey Club General Out-patient Clinic can only provide limited services due to road flooding, the Hospital Authority said on Saturday morning.

Following wet weather overnight, the government earlier urged residents to report flooding to the Drainage Services Department. The government has told employers to make safety arrangements for staff to cope with the situation.

Looking ahead, it said there will be occasional showers and a few thunderstorms on Sunday. It’ll be hot during the day with sunny periods in the following couple of days, the HKO added.

Meanwhile, Shenzhen hoisted a citywide orange rainstorm warning signals – the second highest level in its three-tier system, at 5 pm on Saturday, and the authorities have cautioned residents about the anticipated heavy rainfall, strong gusts of wind and the possibility of landslides.

Zhongshan has upgraded its rainstorm alert to the highest level – a red signal – on Saturday afternoon. Videos circulating online show flooded streets and evacuating residents in the city.

Zhuhai’s Xiangzhou and Doumen districts also issued a red signal, with the services of 101 bus routes disrupted.