The Meteorological Service of Singapore reports on 18 April 1999 for the South East Asian region: “A few hot spots were observed in central Sumatra and northern Kalimantan. The region around Singapore is slightly hazy”. “Monitoring of satellite images and weather reports in the region shows that the region continues to be clear of significant forest fires and smoke haze. Only isolated and occasional hot spots and small smoke haze areas are being detected over central and northern parts of Sumatra”. “Latest reports and analyses have shown that the El Nino 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 Nina event later in the year. In view of the above, 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 Sumatra) would be in their traditionally 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 localized manner remain probable.
Fig.1. Regional Surface Winds and Haze/Hot Spot Map, 18 April 1999
(Source: Meteorological Service of Singapore)
The latest NOAA satellite image showing location(s) of smoke haze and hot spots in Sumatra and Kalimantan.
Daylight pictures are composites from infrared and visible satellite imageries. Colours are added to help identify and highlight various features. Generally, smoke haze shows up in shades of yellow which may appear in streaks fanning out from a small source or as large fuzzy patches. “Hot spots” can be identified as red dots. As the imageries are taken from satellites, overlying clouds if present will invariably obscure areas with smoke haze and hot spots. Strong reflection of sunlight can also give rise to reddish shades over sea areas. These are not related to hot spots.
Fig.2.and Fig.3. Latest NOAA Satellite image for Sumatra and Kalimantan of 18 April 1999
(source: http://www.gov.sg/metsin/hazed.html#sumatra and http://www.gov.sg/metsin/hazed.html#kalimantan)
The Indonesian Meteorological Agency Badan Meteorologi dan Geofisika forecasts rainy and cloudy conditions for Indonesia with maximum temperatures between 28°C (Bandung), 30°C (Samarinda), 27°C (Ujung Pandang) and 31°C (Dili), 34°C (Palembang) and relative humidity ranging from 50% up to 99%.
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.