Meteorological Conditions in South East Asia
23 February 1999
The ASEAN Fire Weather Information System (ASFWIS) is a co-operation between ASEAN and the Canadian Forest Service. It provides maps describing the current fire weather situation in South East Asia. This system is based upon the Canadian Forest Fire Danger Rating System (CFFDRS) (for further infomation to the CFFDRS refer to ASFWIS), and is currently tested on an experimental basis. Studies have shown that the CFFDRS is applicable outside of Canada. Currently it is also used in a modified form in New Zealand (see References). In New Zealand the Fire Weather Indices Fine Fuel Moisture Code (FFMC) and the Initial Spread Index (ISI) represent the fire danger in the scrublands. The Duff Moisture Code (DMC) is also applicable in South East Asia, because it potentially describes the moisture state of the upper peat layers in peat and peat swamp forests. All three parameters may serve as a suitable indicator of forest fire danger in South East Asia.
According to the ASFWIS for 19 February 1999 these parameters show various fire weather conditions over South East Asia. The highest FFMC readings are recorded for northern Thailand, with the FFMC ranging between 90 - 92. Taking the DMC readings into account the fire danger ratings in northern Thailand indicate high fire danger for 19 February 1999.
Survey fligths by the Head of the GFMC over Myanmar and Thailand show extended fire activities in Central-Northern Myanmar and Central Thailand. Most fires are (a) land-use fires (rice paddy burning, shifting cultivation), and (b) large wildfires burning in dry deciduous or semi-deciduous forests of both countries.
Due to substantial rain in Indonesia the fire danger in Indonesia is low.
Fig.1. FFMC output of the ASFWIS
Fig.2. DMC output of the ASFWIS
Fig.3. ISI output of the ASFWIS
These findings are consistent with the current weather reports from the Indonesian Meteorological Agency Badan Meteorologi dan Geofisika which forecasts rainy and cloudy conditions for Indonesia with maximum temperatures between 28°C (Bandung), 33°C (Samarinda), 29°C (Ujung Pandang) and 31°C (Dili), 31°C (Palembang) and relative humidity ranging from 60% up to 99%. The general forecast for whole Indonesia is rainy and cloudy.
The Meteorological Service of Singapore reports on 22 February 1999 for the South East Asian region: "Cloudy skies were observed over many parts of Sumatera and Kalimantan. No hotspots were observed." "Latest reports and analyses have shown that the El Niño event which has brought the region severe dry condition since mid 1997 has weakened considerably. Areas of colder-than-normal sea surface temperature have appeared over parts of central Pacific Ocean, which when taken together with other information points to an increased chance of a La Niña event later in the year". The Meteorological Service states for the near future that: "rainfall in the region is expected to be near or above normal for the next few months. However it should be noted that many parts of Indonesia (Kalimantan and parts of Sumatera) would be in their traditional dry season in the next few months. As such, though extensive and prolonged smoke haze is unlikely for this period, occasional short periods (e.g. a few days) of slight to moderate haze in a more localised manner remain probable".
No fire update information is currently provided by the Integrated Forest Fire Management (IFFM) project in Samarinda (East Kalimantan) and the Forest Fire Prevention and Control Project (FFPCP) in Palembang (Sumatera).
Summary: Although the current fire weather conditions do under normal conditions not favour extensive land clearing by fire or escaping wildfires, the consequences of the large wildfires of 1997-98 must been taken into consideration. These fires had caused extensive degradation of primary and secondary forests along with the spreading of "alang-alang" (Imperata cylindrica) grasslands. These grasslands facilitate the spread of uncontrolled fires over large areas. It can be predicted that in November-December with only moderate fire danger new vegetation fires will occur.
See also the IFFN Country Notes.