WATER surges and mudflows at the foothills of Gunung Jerai in Kedah occurred on Aug 18 between 4pm and 9pm. Mud and soil sediment flow as well as fallen forest debris, including tree trunks and branches, affected many areas.
Rainfall records from the Drainage and Irrigation Department indicated that 281mm of rain occurred within eight hours at the Gunung Jerai rainfall station, which is equivalent to the normal average rainfall for the whole month of August. This heavy rainfall incident represents a more than 70-year return period, ie it will statistically happen only once in 70 years. Heavy rainfall in the area is most likely due to the climate crisis as extreme weather events are becoming more frequent.