SINGAPORE - An unusually high tide is expected on Saturday (Feb 3), and this may increase the chances of flash flooding in the case of heavy rain as drain levels are affected by tides, water agency PUB said in an advisory on Friday.

Tide levels of 3m and above are considered higher than normal, PUB said.

A high tide of 3.4m is expected to set in at 12.45pm on Saturday, following a 3.44m high tide that occurred at noon on Friday.

"During the high tide periods, canals and drains, which lead to the sea and are therefore influenced by tides, will see high water levels," said PUB. "Seawater may also overflow from the drains and flood the roads."

Should there be heavy rain at the same time as the high tide, flash floods may occur in low-lying coastal areas such as Jalan Seaview, Meyer Road, Fort Road and Tanjong Rhu.

PUB said that Friday's high tide led to seawater flowing inland through the roadside drain onto the junction of Amber Road and Mountbatten Road.

The waters on the road subsided at about 1pm and PUB officers were on standby at the site in order to clear choking in drains if there were any. PUB also warned motorists not to drive into flooded areas, and advised pedestrians against entering such areas.

"We advise the public to exercise care should flash floods occur, and avoid stepping into or driving into any flooded areas," said PUB.

The advisory comes after flash floods occurred on several days last month, with the worst incidences on Jan 8, where unusually heavy rain coupled with a monsoon surge led to flash floods in nine locations.

PUB said it will provide updates on Saturday to alert motorists and the public. It advised the public to stay tuned to radio broadcasts and check PUB's Facebook page or mobile app "MyWaters" for flood updates.