The Meteorological Service of Singapore reports on 31 May 1999 for the South East Asian region: “Cloudy conditions were observed over northern Borneo and most parts of Sumatra. Hot spots were observed over central Sumatra”.
Fig.1. Regional Surface Winds and Haze/Hot Spot Map, 31 May 1999
(Source: Meteorological Service of Singapore)
The latest NOAA14 satellite image showing hot spot locations in Sumatra. “Hot spots” can be identified as red dots.
Fig.2. Latest NOAA Satellite image for Sumatra of 31 May 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). 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 31 May 1999 these parameters show various fire weather conditions over South East Asia. The Fine Fuel Moisture Code (FFMC) reaches values from 85 to 89 in southern and central Thailand, southern Vietnam, western and central Sumatra, western Malaysia and Sulawesi.
Fig.3., 4.and 5. FFMC, ISI and DMC output of the ASFWIS, 31 May 1999
The Indonesian Meteorological Agency Badan Meteorologi dan Geofisika publishs the Indonesia Daily Forecasting for 2 June 1999. For the representative selected areas metereological data are provided as follows:
Summary: Although the current fire weather conditions do under normal conditions not favour extensive land clearing by fire or escaping wildfires in Indonesia, 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.