PETALING JAYA - The massive flooding of Peninsular Malaysia's east coast states is not just due to extremely heavy rainfall - the moon has something to do with it as well.
According to the Malaysia Meteorological Department (MMD), the gravitational pull of the moon can lead to higher than normal high tides, more so when it is at its closest to the earth, a position also known as perigee.
The moon was at perigee at Dec 24 at 16:44 GMT (or 12.44am on Christmas Day here), where it was as close as 364,791km from Earth, appearing as a super moon, or a larger than usual moon, even to the most casual of observers.
The gravitational pull of the moon can generate extreme high tides at this position.
MMD spokesman Dr Mohd Hisham Anip said that it was understood that continuous strong winds brought lots of moisture and created dense clouds in our region.
"The wind came from the western Pacific and China, and we haven't understood how this year differs from previous years," Dr Mohd Hisham said yesterday.
He said more studies needed to be conducted on the effects of high tide when augmented by the new moon and perigee.
"The good news is that the peak of the high tide is over, which was on Dec 23 and 24," he said.
"All we know is the high tide is coming and it is higher than usual," he said, adding that extremely heavy or prolonged rain that coincides with higher than usual tides is usually a recipe for flooding as the river mouth is effectively "blocked" by a wall of water.
MMD said further episodes of high tide is expected to come again on Monday, and this would probably affect Pahang, Johor and Sarawak.
The not so good news is that the rainy season is expected to end only by the middle or end of February.
Dr Mohd Hisham also revealed that in a "normal" month, rainfall averages between 500mm to 600mm in a month for the east coast.
"But areas such as Kuala Krai in Kelantan, Kuantan in Pahang and Gong Badak in Terengganu received more than 1,000mm of rainfall this month."