Subseasonal Weather Outlook and Review

1.1    Moderate Northeast Monsoon season was established in the region in December 2014, bringing dry and cool weather to most parts of the Mekong Sub-region of Cambodia, Lao PDR, Myanmar, northern Thailand and Vietnam. In the southern ASEAN region, the prevailing rainy season affected most parts of the southern ASEAN region.

1.2    Super Typhoon ‘Hagupit’ which was the most intense tropical cyclone of the year, developed to the east of the Philippines in the last week of November 2014. It strengthened as it tracked westwards, making landfall over the provinces of Samar and Masbate in the Philippines on 6 and 7 December 2014 respectively. ‘Hagupit’ weakened rapidly after making landfall and dissipated rapidly over the South China Sea, southeast of Vietnam. On 29 December 2014, another Tropical Storm ‘Jangmi’ affected the Philippines, making landfall over Mindanao. ‘Jangmi’ tracked across the Philippines before dissipating over South China Sea. Both ‘Hagupit’ and ‘Jangmi’ affected up to a million people, and destroying hundreds of houses along their path.

1.3    On 13 January 2015, Typhoon “Mekkhala” developed over the Western Pacific Ocean, and continued its westward track afecting the eastern part of Luzon and Visayas in the Philippines a few days later. Typhoon “Mekkhala” made landfall near eastern Samar, the Philippines on 17 January 2015, and weakened rapidly into a tropical depression as it moved north-eastwards, dissipating over water on 21 January 2015 away from Luzon Islands.

1.4    During the second half of December 2014, the strengthening of north-easterly winds over the South China Sea, or a monsoon surge, affected the region on a few occasions. The monsoon surges brought wet and windy conditions to parts of the southern ASEAN region. Continuous heavy showers of rain fell over most parts of Peninsular Malaysia, and led to severe flooding in the eastern coastal States of Terengganu, Pahang, and Kelantan with around 250,000 people displaced from their homes. Several districts in Indonesia and southern Thailand were also affected by floods due to the several days of continuous rainfall.

1.5    In December 2014, many parts of the southern ASEAN region received more than 100% of normal rainfall with the exception of southern Sumatra and western Borneo where less than 100% of normal rainfall was received. In contrast, most parts of the northern ASEAN region such as Thailand, Myanmar and Cambodia received less than 50% normal rainfall. Many parts of the Philippines received more than 125% of normal rainfall due to the passage of Super Typhoon ‘Hagupit’ and Tropical Storm ‘Jangmi’. The regional rainfall distribution for December 2014 is shown in Fig. 1A.

2.   Review of Land/Forest Fires and Smoke Haze Situation

1.1    Moderate Northeast Monsoon season was established in the region in December 2014, bringing dry and cool weather to most parts of the Mekong Sub-region of Cambodia, Lao PDR, Myanmar, northern Thailand and Vietnam. In the southern ASEAN region, the prevailing rainy season affected most parts of the southern ASEAN region.

1.2    Super Typhoon ‘Hagupit’ which was the most intense tropical cyclone of the year, developed to the east of the Philippines in the last week of November 2014. It strengthened as it tracked westwards, making landfall over the provinces of Samar and Masbate in the Philippines on 6 and 7 December 2014 respectively. ‘Hagupit’ weakened rapidly after making landfall and dissipated rapidly over the South China Sea, southeast of Vietnam. On 29 December 2014, another Tropical Storm ‘Jangmi’ affected the Philippines, making landfall over Mindanao. ‘Jangmi’ tracked across the Philippines before dissipating over South China Sea. Both ‘Hagupit’ and ‘Jangmi’ affected up to a million people, and destroying hundreds of houses along their path.

1.3    On 13 January 2015, Typhoon “Mekkhala” developed over the Western Pacific Ocean, and continued its westward track afecting the eastern part of Luzon and Visayas in the Philippines a few days later. Typhoon “Mekkhala” made landfall near eastern Samar, the Philippines on 17 January 2015, and weakened rapidly into a tropical depression as it moved north-eastwards, dissipating over water on 21 January 2015 away from Luzon Islands.

1.4    During the second half of December 2014, the strengthening of north-easterly winds over the South China Sea, or a monsoon surge, affected the region on a few occasions. The monsoon surges brought wet and windy conditions to parts of the southern ASEAN region. Continuous heavy showers of rain fell over most parts of Peninsular Malaysia, and led to severe flooding in the eastern coastal States of Terengganu, Pahang, and Kelantan with around 250,000 people displaced from their homes. Several districts in Indonesia and southern Thailand were also affected by floods due to the several days of continuous rainfall.

1.5    In December 2014, many parts of the southern ASEAN region received more than 100% of normal rainfall with the exception of southern Sumatra and western Borneo where less than 100% of normal rainfall was received. In contrast, most parts of the northern ASEAN region such as Thailand, Myanmar and Cambodia received less than 50% normal rainfall. Many parts of the Philippines received more than 125% of normal rainfall due to the passage of Super Typhoon ‘Hagupit’ and Tropical Storm ‘Jangmi’. The regional rainfall distribution for December 2014 is shown in Fig. 1A.

2.   Review of Land/Forest Fires and Smoke Haze Situation