BANDAR SERI BEGAWAN (Borneo Bulletin/Asia News Network): Air quality readings in the Sultanate are still within a good range due to favourable weather conditions, said the Department of Environment, Parks and Recreation (JASTRe) on Monday (Oct 2).
As of 4pm on Monday, the Sultanate’s pollutant standard index (PSI) as stated in JASTRe’s social media recorded a ‘good’ reading ranging from 10 in the Brunei-Muara District, to Tutong District (14), Belait District (26) and 19 in Temburong District. A PSI reading of between 0-50 is good level.
However this will depend on the severity of the fires in Kalimantan.
Meanwhile, according to the Asean Specialised Meteorological Centre (ASMC) based on satellite imagery, moderate to dense haze and unhealthy levels of air quality in Central and South Kalimantan was reported by a few stations.
The ASMC said dry weather persisted over most of the southern Asean region overnight, with isolated showers and cloudy conditions observed over northern Sumatra and Peninsular Malaysia.
The thick cloud covering over southern and central Sumatra cleared yesterday, and moderate to dense smoke haze was observed over a large area and spreading northwards. ‘Unhealthy’ to ‘Very Unhealthy’ levels were reported by air quality stations there overnight.
Over the northern Asean region, cloudy conditions with isolated showers were observed overnight.
Heavy rainfall and strong winds were observed in the northern and central parts of the Philippines due to the influence of Typhoon Koinu.
Over the next few days, dry conditions are forecast to prolong over most parts of southern and central Sumatra, as well as southern Kalimantan. Elevated hotspot activities and moderate to dense smoke haze are expected to persist over the fire-prone areas in southern and central Sumatra, as well as southern Kalimantan.
ASMC said the prevailing winds are forecast to blow mainly from the southeast to southwest, increasing the risk of transboundary haze occurrence.
Shower activities are expected to prevail and the hotspot activity likely to remain subdued in the northern Asean region.
The prevailing winds over the Mekong sub-region are forecast to be light and variable while the prevailing winds over the Philippines are expected to blow from the southwest due to the influence of Typhoon Koinu as it tracks northwestward.
Meanwhile the Brunei Darussalam Meteorological Department said the Sultanate has entered the inter-monsoon period, the transition period after the Southwest Monsoon and before entering the Northeast Monsoon.
The inter-monsoon period is expected to last until the end of November.
During this period, the absence of prevailing monsoonal wind flow has allowed local wind effects to play an important role in governing the daily weather.
Based on climatological records, the frequency of thunderstorms occurrences is the highest during the inter-monsoon period in comparison to the other months, whereas the average rain days for October is 21 days and for November is 22 days.
Throughout this period, the country normally experiences fair weather in the morning and isolated coastal showers around midday.
Thunderstorms occur over the inland during the afternoon, spreading and affecting coastal and sea areas at night, and may persist to early morning of the following day.
Light wind blows from variable directions in the morning and at night, and from Northwest in the afternoon; and the wave condition at sea is generally at slight state.
However, with the El Niño conditions observed, Brunei typically experience suppressed rainfall activity with increasing air temperature.
Hotter and drier weather conditions are likely to happen during the peak of the El Niño event during end of the year to early next year. Maximum daily temperatures may reach up to 34.0 degree Celsius or more during the afternoon.
Excessive Hot Weather (EHW) or heatwave in the Sultanate tends to occur during El Niño episodes.