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1.   Review of Regional Weather Conditions in May 2015
1.1    Inter-Monsoon season, which is characterised by light wind and wet weather conditions, prevailed over the ASEAN region in May 2015. The northward migration of the monsoon trough during the period brought persistent shower activities over the northern ASEAN region.

1.2    Super Typhoon Noul, which developed in early May 2015 from a tropical depression in the western Pacific Ocean made landfall over Cagayan in northeastern Luzon Island in the Philippines on 10 May 2015. “Noul” continued to track northeast towards Okinawa, Japan before dissipating in the North Pacific Ocean.

1.3    In southern ASEAN, wet weather conditions generally prevailed until mid-May. Due to the northward migration of the monsoon trough, the shower activities had gradually eased off by late May.

1.4    In May 2015, most parts of northern ASEAN region received less than 50% of normal rainfall. Most of the southern ASEAN region, except Java, received 50 – 75 % of normal rainfall. The regional rainfall distribution for May 2015 is shown in Fig. 1A.


Fig. 1A: Percentage of Normal Rainfall for May 2015


2.   Review of Land/Forest Fires and Smoke Haze Situation
2.1    Persistent shower activities prevailed in May 2015 over the ASEAN region. The hotspot activities were generally subdued, and there were no occurrences of significant transboundary haze during the review period

2.2    During periods of drier weather conditions in May 2015, isolated hotspots with localized smoke haze were observed on a few days. Satellite images depicting some of the hotspot activities over the ASEAN region in May 2015 are shown in Figs. 2A to 2D.


Fig. 2A: NOAA-18 satellite image on 4 May 2015 shows widespread shower activities which helped to subdue hotspot activities.


Fig. 2B: NOAA-18 satellite picture on 14 May 2015 shows showers over most parts of Kalimantan which helped subdue the hotspot activities.

Fig. 2C: NOAA-18 satellite picture on 30 May 2015 shows wet weather over most parts of Peninsular Malaysia and central Sumatra, with isolated hotspots over cloud-free areas.


Fig. 2D: NOAA-18 satellite picture on 29 May 2015 shows localised smoke haze emanating from hotspots in Riau province, central Sumatra.


2.3    The hotspot charts for May 2015 for

  1. Cambodia, Myanmar, Thailand, Lao PDR and Vietnam;
  2. Sumatra, Borneo and Peninsular Malaysia; and
  3. Java, Sulawesi and the Philippines

        are shown in Figs. 2F to 2H respectively


Fig. 2F: Hotspot Counts in Cambodia, Lao PDR, Thailand, Vietnam, Myanmar for May 2015.


Fig 2G: Hotspot Counts in Sumatra, Borneo and Peninsular Malaysia for May 2015.


Fig. 2H: Hotspot Counts in Java, Sulawesi, Philippines for May 2015.