SINGAPORE - More rain pelted western Singapore in three hours on Tuesday morning (Aug 24) than the country had previously recorded for the whole month of August.
National water agency PUB said the heaviest rainfall recorded in the morning was at the Bukit Panjang Road rainfall station, which saw 159.8mm of rainfall from 7.50am to 10.40am.
"This corresponds to 109 per cent of Singapore's average monthly rainfall in August, and lies within the top 0.5 per cent of maximum daily rainfall records since 1981," said PUB.
Rainfall was found to be the heaviest over the northern and western parts of the country, said the National Environment Agency (NEA) in a Facebook post.
As at noon on Tuesday, 239.8mm of rainfall was recorded in Mandai and 226.2mm in Bukit Panjang. They are the highest daily total rainfall for the month to date. The previous high in August was 181.8mm, which was recorded in Changi on Aug 22, 1983.
The storm was most intense over Mandai, with 84.8mm of rainfall recorded as at noon on Tuesday.
This is slightly lower than the highest rainfall intensity of 95.8mm recorded in Choa Chu Kang last Friday.
Temperatures also dipped on Tuesday morning, with Newton seeing the lowest temperature at 21.3 deg C.
The showers were due to prevailing winds from the south and south-west converging around the vicinity of Singapore.
The heavy rain saw water levels in drains and canals reach 90 per cent in some parts of the country.
PUB issued flood-risk warnings for several locations due to the heavy downpour, including the Upper Bukit Timah area, Woodlands and Sunset Drive.
The storm caused a flash flood along Dunearn Road leading from Sime Darby to Binjai Park at 10.08am, causing roads to be impassable by traffic.
PUB's quick response teams were on standby at the location to close off a portion of the road and to help divert traffic, said the agency.
The flash flood subsided at 10.50am.
In videos tenants and shoppers took, people could be seen walking in almost ankle-deep rainwater at the first basement level of Bukit Timah Plaza.
The Straits Times understands that the perimeter drain in front of the entrance leading to the lower levels of the mall was overwhelmed, causing water to leak inside.
Ms Dione Yap, the owner of clothing store Fashion Loft at the first basement level, said she had avoided turning up at the mall earlier due the floods in the area.
She was there at 3pm to check on damage to her shop and merchandise.
"The floor in my shop was damaged, so I have to get the contractor to return and redo the renovation I just did," said the 49-year-old, who had closed her shop for renovation works to be carried out.
Hairstylist Ng Wee Tian, 27, who works in the hair salon next to Ms Yap's shop, helped to mop up some of the water and bought towels to stop more from entering the shop.
The hair salon was not affected.
Heavy rain last Friday had also caused a flood at about 7am at the junction of Tampines Avenue 10 and Pasir Ris Drive 12, which is not a flooding hot spot.
The incident caused vehicles to become partially submerged, leaving 13 drivers stuck at the road junction.
The Singapore Civil Defence Force sent two fire engines and two ambulances, with firefighters rescuing five people from four cars in just under an hour.
Thundery showers last Friday were caused by a clash of winds blowing from the north and south of Singapore.
The Meteorological Service Singapore has said that more thundery showers are expected for the rest of August, with the monsoon rain band hovering over the equatorial South-east Asia region where Singapore is.
In the Facebook post, NEA said a climate phenomenon called the Indian Ocean Dipole could have contributed to the recent rain.
"The Indian Ocean Dipole is currently in a negative state, which typically brings more rainfall to the region," added the NEA.
The negative phase of the Indian Ocean Dipole brings rainier weather over South-east Asia due to changes in atmospheric pressure and sea surface temperatures across the Indian Ocean.
"For the next few days, thundery showers are expected between the morning and early afternoon," said NEA.