The worsened haze in western parts of Peninsular Malaysia and western Sarawak over the weekend is a result of an increasing number of hotspots in Sumatra and Kalimantan.
Although Indonesia denied the fact, data on ASMC’s website showed that hotspots in Sumatra have drastically increased from 52 spots on Saturday (Sept 7) to 206 on Sunday (Sept 8).
In fact, the hotspots were so bad in Indonesia that a level 3 alert was announced for Sumatra by ASMC yesterday.
Level 3 means there are more than 250 hotspots in two consecutive days with dense smoke plumes, persisting dry weather and prevailing winds blowing towards Asean countries.
Currently, smog in several Indonesian provinces is being carried to western Sarawak and Peninsular Malaysia by southwest monsoon winds.
Those provinces are Riau, Jambi, South Sumatra, Lampung and West, Central, and South Kalimantan
Throughout the Southwest Monsoon period, there will be reduced rainfall and hot and dry temperatures in most areas of Malaysia.
Basically, the optimum weather to exacerbate haze conditions.
If the hotspots in Sumatra and Kalimantan are not controlled, MetMalaysia expects the transboundary haze to remain in Malaysia until the end of the Southwest Monsoon.
The Southwest Monsoon is expected to end sometime between the end of September and early October.
During the monsoon transition period in early October, MetMalaysia expects wetter weather with rain, thunderstorms and strong winds in the evenings.
Rain will be especially heavy in the west coast and central areas of the peninsula, the west coasts of Sabah and the west coast and central areas of Sarawak.
Which will wash away all that smoke, haze and smog!
To get a better picture of how exactly the winds are blowing haze from hotspots in Indonesia to Malaysia, this website that visualises airflow between Asean countries in real-time might make things a little clearer.