Monthly Archives: June 2015

June 30, 2015

Review of Regional Weather and Smoke Haze for May 2015

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.F

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 30 May 2015 shows wet weather over most parts of Peninsular Malaysia and central Sumatra, with isolated hotspots over cloud-free areas.

2.3 The hotspot charts for May 2015 for

Cambodia, Myanmar, Thailand, Lao PDR and Vietnam;
Sumatra, Borneo and Peninsular Malaysia; and
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.

June 23, 2015

Alert 1 250615 Start of Dry Season Southern ASEAN

The dry season for the southern ASEAN region has started

The Southwest Monsoon has onset in the region in early June 2015. In recent days, the region including Sumatra and Kalimantan have been experiencing dry weather conditions, signalling the start of the traditional dry season in the southern ASEAN region.

The prevailing Southwest Monsoon is expected to persist over the next few months. The prevailing El Nino could also exacerbate the dry season. During this period, extended periods of drier weather can be expected, which could lead to elevated hotspot activities in the fire-prone areas.

June 18, 2015

4th ASEAN COF (21-22 May 2015, Jakarta)

The fourth ASEANCOF meeting was held in the Agency for Meteorology Climatology and Geophysics, in Jakarta Indonesia from 21-22 May 2015. It was attended by representatives of the National Meteorological Services from the ASEAN Member countries: Myanmar, Malaysia, Singapore, Vietnam, the Philippines and Indonesia. The meeting was also attended by representative from the WMO secretariat and experts of the WMO Global Producing Centers: UK Met Office, NOAA, Bureau of Meteorology Australia, and CPTEC Brazil. The forum was preceded by a week-long training and working session organized by NOAA with support from USAID. WMO provided co-sponsorship and technical support to ASEANCOF-4.

Consensus Outlook for the Southwest Monsoon (JJA 2015) Rainfall and Temperature over Southeast Asia

For the upcoming Northern Hemisphere summer (Jun-Jul-Aug) season in 2015, there is strongly enhanced probability for below normal rainfall over the southern part of the Maritime Continent and the eastern margins of mainland Southeast Asia. Over the remainder of mainland Southeast Asia there are slightly enhanced probabilities for normal to below normal rainfall, while over the Philippines there are slightly enhanced probabilities for normal to above normal rainfall.

Above normal temperatures are most likely over much of the Southeast Asia region for the Northern Hemisphere summer, with the highest probabilities over the western Maritime Continent and mainland Southeast Asia. Below normal temperatures are slightly favoured over a relatively small area in the south-eastern part of the Maritime Continent.

Acknowledgements

The forum appreciates the participation of the ASEAN Member countries in conveying their national-level forecast. The forum also appreciates the products and expertise made available from the GPCs for this climate outlook forum. The forum thanked the continuous support from the WMO secretariat and also to the USAID for providing sponsorship for this event.

Meeting Documents

ASEAN COF 4 Meeting Report