Update On El Nino And Haze Situation

Singapore, 08 August 2014 – The tropical Pacific Ocean surface temperatures have continued to warm but gradually eased in recent weeks, slowing down the development of El Niño conditions. However, with most global climate models forecasting the continued warming of the tropical Pacific Ocean in the coming months, a weak to moderate El Niño [1] is still likely to develop in the last quarter of 2014, according to the Meteorological Service Singapore.

2Despite the observed warming over the tropical Pacific Ocean over the last few months, a number of atmospheric indicators of the El Niño, such as wind flow and cloudiness, have remained largely neutral. A plausible explanation for the lack of atmospheric response is that the warming has occurred over almost the entire tropical Pacific Ocean, including the sea areas in our region. During a typical El Niño development, warming is observed mostly in the eastern and central parts of the tropical Pacific Ocean.

3In the last few months the sea surface temperatures in our region have been warmer than normal, leading to increased convection and formation of rain clouds. This has contributed to the relatively wet weather conditions in Singapore and the surrounding region during the current Southwest Monsoon season. However there were still occasional periods of dry weather in June and July that led to an escalation of hotspot activities in Sumatra. During this period the western parts of Peninsular Malaysia were affected by transboundary smoke haze from Riau province in Sumatra on some days. There was also a sharp increase in hotspot activities in western Kalimantan due to drier weather in the second half of July. Singapore was not affected as southerly winds over our surrounding region helped to keep the haze away.

4As the Southwest Monsoon continues to prevail in the region till around October, extended dry and warm periods can be expected. Developing El Nino conditions could exacerbate the dry weather conditions and increase the risk of occurrence of transboundary smoke haze from land and forest fires in the region. Singapore could be affected if the prevailing winds blow the smoke haze from Sumatra or Kalimantan toward us.

5With the forecast of a weak to moderate El Nino in the last quarter of the year, it should be noted that the El Niño is known to have relatively less impact on weather patterns in Singapore and the nearby region during the Northeast Monsoon season (typically from late November to March). The risk of drier weather conditions due to the El Niño is thus expected to be lower towards the end of the year.

6For the National Day weekend, short-duration thundery showers are expected mainly in the late morning and early afternoon. With the prevailing southerly winds and rain showers also expected in the surrounding region, Singapore is not likely to be affected by transboundary smoke haze. Air quality is expected to be in the Moderate range this weekend.

7Meteorological Service Singapore will continue to closely monitor the conditions in the tropical Pacific that lead to the development of the El Niño, as well as the regional weather and haze situation, and provide updates if necessary.

[1] The El Niño refers to the abnormal warming of the tropical Pacific Ocean and is known to disrupt normal weather patterns in various regions of the world. In Southeast Asia, the effect of the El Niño is prolonged drier and warmer weather in large parts of the region

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