Heavy rain hits Singapore for second straight day

The recent severe weather impacting Singapore continued for a second consecutive day with strong winds sending a dumpster and even some boats flying in the air at East Coast Park yesterday.

Heavy rain continued to blanket the island after first falling hard on Tuesday, when hail hit several parts of the island, including Yishun and Seletar.

Videos circulating online revealed the strength of the fierce gust yesterday afternoon which buffeted parts of Marine Parade as well.

Winds picked up at least three small boats at the National Sailing Centre (NSC) before sending them towards the person filming the incident.

An NSC spokesman told The Straits Times: "A strong gust of wind together with a waterspout came through NSC and left a trail of damage. It was fortunate that sailors were recalled... and waited under shelter when the siren was sounded earlier."

Assistant Professor Winston Chow, a weather researcher from the National University of Singapore's geography department, said what likely happened was that downdrafts - which can exceed 70kmh to 80kmh during intense storms - were centred over the East Coast area.

The storm also uprooted a tree at Neptune Court condominium yesterday afternoon. It blocked traffic along Marine Parade Road towards Parkway Parade shopping centre, leaving only one lane in the opposite direction open until 9.30pm when the roads were clear again.

The strong winds follow thundery showers which pummelled many parts of Singapore on Tuesday afternoon.

The Meteorological Service Singapore (MSS) said the highest rainfall, at 46.6mm, was recorded between 4.55pm and 5.25pm at Sembawang on Tuesday. That is 20 per cent of Singapore's mean monthly rainfall for January falling in just 30 minutes, according to National Environment Agency figures. The strongest wind gust at 70.9kmh was also recorded in Sembawang.

The Straits Times understands one person reported suffering cuts and abrasions from an incident involving a tree in Yishun Avenue 5.

A weather radar image provided by MSS showed some thunderstorm clouds that formed in that area reached a height of 14km, higher than the 10km to 12km that most thunderstorm clouds reach.

"Towering thunderstorm clouds form when there is very strong daytime heating of the land surface, coupled with wind convergence," said MSS.

"These clouds have powerful downdrafts that cause some hailstones to reach the ground quickly before melting."

Residents in Yishun and Seletar had reported seeing pieces of ice, the size of five-cent and 10-cent coins, falling in the area on Tuesday including at Seletar Airport. The recent severe weather was preceded by a monsoon surge in the South China Sea and surrounding region, which saw temperatures dipping to a low of 22.8 deg C on Jan 10.

Professor Benjamin Horton said the hail was caused by "upper atmospheric conditions of the previous few days, to weeks, that allowed this particular thunderstorm cloud to form hailstones".

70.9kmh

Tuesday's strongest wind gust , which was recorded in Sembawang.

The principal investigator at Nanyang Technological University's Earth Observatory of Singapore added that hail also fell in Singapore on four occasions from March 2008, and these were associated with heavy thunderstorms.

"The timing of the events indicates no link to the monsoon season, which commonly occurs from November to January," said Prof Horton.

The National Parks Board said there were more than 200 reported incidents of fallen trees and snapped branches during Tuesday's "extreme storm". Most were cleared by 8pm that day.

Its streetscape group director Oh Cheow Sheng said: "Tuesday's storm event is an example of extreme storms consisting of strong winds of up to 70kmh or more and heavy rains that we have seen in recent years."

These included a storm in 2011 that destroyed 10,000 forest trees in the Mandai area.