THE 24-hour heavy downpour that began late night on Friday is the same as the average rainfall of a month, said the Environment and Water Ministry, which is a one in 100-year weather event.

Ministry secretary-general Zaini Ujang said the phenomenon occurred because of monsoon flow factors and a low pressure weather system that achieved the level of a tropical depression that formed in the South China Sea.

On December 12, the system was detected by the Meteorological Department.

On December 16, the system entered Pahang and moved across the west coast of the peninsula, causing a rise in humidity and continuous heavy rain in almost every state.

“It is an exception, because during the monsoon season, only states in the east coast will receive heavy rain,” said Zaini.

“But this time, the entire peninsula, especially the central and northern regions, have seen continuous heavy rain.”

He said Sentul recorded the highest amount of rainfall at 363mm, followed by Sungai Bonus in Jalan Tun Razak (273mm), Jinjang (258mm) and Gombak (247mm).

“Kuala Lumpur’s annual rainfall is 2,400mm, so the rainfall yesterday exceeded the average rainfall for a month. It is something beyond expectation and only occurs once every 100 years.”

The heavy rainfall is expected to end as the low pressure weather system in the Straits of Malacca has moved away from the country towards the Andaman Sea.

“Based on the latest weather model analysis, the rainfall will lessen today, but there are still areas receiving wet weather throughout the day,” said Zaini.

“Based on the analysis, there will be no continuous heavy downpour warning for the Klang Valley this evening.”

Floods are also reported in Perak, Pahang, Terengganu, Kelantan, Malacca and Negri Sembilan. – Bernama, December 19, 2021.