Category Archives: News

Below Average Rainfall Expected in January and February 2015

Singapore, 22 January 2015 – Singapore has been experiencing fewer rain days since mid-January 2015 with the onset of the dry phase of the Northeast Monsoon. With low rainfall forecast for the rest of the month, total rainfall for January 2015 is expected to be significantly below average. Below average rainfall is also forecast for February.

2The Northeast Monsoon typically comprises a wet phase from late November to January, followed by a dry phase in February. The dry phase is characterised by drier and cooler weather and generally windy conditions. This year, the onset of the dry phase was slightly earlier than usual. A contributing factor is that of stronger winds in the surrounding region which have caused an earlier southward shift of the monsoon rain belt away from Singapore. This followed a relatively wet November and December 2014 where the total rainfall was 27% and 20% respectively above the long-term average.

3From 1 to 21 January 2015, the total rainfall averaged across rainfall stations islandwide was 83.7mm. At the Changi climate station, rainfall of 79.6mm was recorded, significantly below the long-term average of 242.4mm for January. The average daily temperature over the same period is comparable to that of recent years, and it has been more windy.

4For the rest of January 2015, generally dry and windy conditions are expected, with mainly localised short-duration showers on a few days. The total rainfall for January 2015 is expected to be approximately 40-60% below the long-term average of 242.4mm. Significantly below average rainfall for January was last recorded in 2014 and 2010.

5For February, which is climatologically one of the driest months of the year, below average rainfall is forecast. However, the current assessment is that the dry phase of the Northeast Monsoon season this year is not likely to be of the same degree of dryness as that experienced during the record dry spell of 2014. PUB would also like to urge the community and industries to use water wisely and conserve precious water resources.

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JOINT ADVISORY BETWEEN PUB AND NEA

Singapore, 18 November 2014 – Singapore can expect more rainy days ahead with the onset of the Northeast Monsoon later this month, according to the Meteorological Service Singapore (MSS). The first half of November 2014 has been wetter than usual in many parts of the island, with 188mm of rainfall recorded at the Changi climate station. Rainfall for November and December 2014 is expected to be about 20% above the long-term average of 256.6mm and 288.4mm respectively.

2The Northeast Monsoon season typically comprises a wet phase between late November and January, followed by a drier phase in February. The wet phase is characterised by short-duration moderate to heavy thundery showers mainly in the afternoon and evening, and about two to four episodes of monsoon surges. Monsoon surges refer to the steady strengthening of northeasterly winds blowing from the South China Sea. These monsoon surges usually bring periods of prolonged widespread moderate to heavy rain lasting between two and five days, occasionally windy conditions, and cooler temperatures.

3MSS will issue warnings when heavy rain or prolonged monsoon rain is expected, in addition to the regular weather forecast. This will help the public to better prepare for heavy rain. Heavy rain coinciding with high tides could lead to localised flash floods in low-lying areas. The public are advised to exercise caution during the Northeast Monsoon season as flash floods may occur in the event of heavy rainfall.

Enhancing Operational Preparedness

4In preparation for the upcoming Northeast Monsoon, PUB, the national water agency, works closely with NEA’s Department of Public Cleanliness (DPC) to ensure that our drains remain free flowing.

5Apart from reminding the construction industry to conduct checks on the public drains in the vicinity of their respective construction sites, PUB is also inspecting some 100 major construction worksites to ensure that the drains around the construction sites are free of debris and smooth-flowing.

Online Flood Monitoring Efforts

6As part of PUB’s flood monitoring efforts, a network of 161 closed circuit television (CCTV) cameras to monitor road conditions in low-lying areas and hotspots in real time. Some of these CCTV images are also available for the public to view via PUB’s website or PUB’s mobile app MyWaters and they are refreshed every five minutes.

7PUB has increased the number of water level sensors from 158 last year to 171 this year. Installed in the major drains and canals, these water level sensors provide real-time data on water levels, and serve to enhance PUB’s live monitoring of site conditions during heavy storms and enable quick response. PUB will be increasing the number of water level sensors to 200 by the first quarter 2015. Information from all water level sensors is also available for public viewing. The public can subscribe to the free SMS alert service via PUB’s website or get updates on rising water levels in the drains or canals on PUB’s Facebook, Twitter and PUB’s MyWaters mobile app.

Keeping the Public Informed

8In October, PUB officers had distributed flood advisories to some 500 residents and shop-owners in low-lying areas, some of which are subject to tidal influence. Besides alerts on the possibility of flash floods, the advisories also provide tips on the precautions that residents and shop owners could take to protect their belongings, such as by storing them on higher ground or placing sandbags or flood boards to block floodwaters.

9To obtain the latest weather reports, including heavy rain warnings, the public can tune in to radio traffic watch broadcasts, call MSS’ weather forecast hotline at 65427788, visit the NEA website at www.nea.gov.sg and access NEA’s mobile app MyENV or subscribe to the heavy rain warning SMS alert service provided by the MSS.

10During heavy rain events, the public can also be updated on flood alerts through various channels such as PUB’s Facebook at www.facebook.com/PUBsg, PUB’s Twitter at www.twitter.com/PUBsingapore, and PUB’s mobile app MyWaters. Motorists can also look out for flood updates via electronic signage on roads.

11Members of the public can call PUB’s 24-hour Call Centre at 1800-284 6600 to report on any flood situation. The public can also visit PUB’s website at http://www.pub.gov.sg/managingflashfloods to access the CCTV images and information on water levels in key canals and drains.

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Singapore, 27 October 2014 – Singapore and the surrounding region can expect more rain in the coming weeks, as the Southwest Monsoon has transitioned to Inter-Monsoon conditions over the past week. This signals the end of the traditional dry season in the region, and the likelihood of transboundary haze affecting Singapore for the rest of the year will thus be low, according to the Meteorological Service Singapore.

2 The Inter-Monsoon period normally lasts from October to November, and is characterised by more rainfall and light winds that are variable in direction. The increased rainfall will help alleviate the hotspot and haze situation in Sumatra and Kalimantan. During this period Singapore may experience occasional slight haze, mainly in the morning, on some days due to the accumulation of particulate matter in the air under light wind conditions. The haze situation is expected to improve further with the onset of the rainy season brought by the Northeast Monsoon in early December.

3 Based on the forecasts from most global climate models, a weak El Nino is still likely to develop towards the end of 2014 or early 2015. However, past El Nino events that form at that time of the year have been shown to have less impact on rainfall patterns in Singapore and the nearby region.

4 With the improvement in the haze situation, the National Environment Agency (NEA) will discontinue issuing the daily Haze Forecast and Health Advisory after Monday, 27 October 2014. Air quality readings will still be available hourly, from 7am to 11pm, on the haze microsite (www.haze.gov.sg), the NEA corporate website (www.nea.gov.sg), and on the MyENV application. Air quality readings from 12am to 6am will be made available at 7am on the same day. NEA will continue to monitor the weather and haze situation in the region, and update the public when necessary.

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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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Singapore, 30 May 2014 – The Meteorological Service Singapore (MSS) is forecasting weak to moderate El Niño conditions to develop in the next few months, bringing drier and warmer conditions to Singapore and the region. Rainfall for Singapore over the coming Southwest Monsoon season between June and September 2014 could range between 10 – 40% below average, while the average daily temperature is expected to be about 1°C above average (refer to Table 1 for average values).

2The 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. (further information on the El Niño is given in Annex A).

3Since March 2014, the sea-surface temperature in the tropical Pacific has been warming steadily. This is a known precursor to an El Niño build-up. Based on the latest warming trend in the Pacific Ocean, as well as the computer model forecasts from various global climate centres, El Niño conditions could develop as early as end July. The strength of the El Niño is forecast to be weak to moderate and is likely to peak in the last quarter of the year. Typically, an El Niño which peaks late in the year will start to weaken in the first half of the following year.

4Based on past El Niño events of moderate strength, Singapore is expected to experience below average rainfall during the June to September period, which is also the traditional dry season in the region that is brought about by the Southwest Monsoon. In 1963, when an El Niño of moderate strength occurred, Singapore’s rainfall total over this four-month period was reduced by almost 40% compared to the long-term average. In the more recent occurrence of a moderate El Niño in 2009, the corresponding figure was about 20% below the long-term average. Average daily temperature for the same period in 2009 was 1.1°C warmer than the long-term average of 27.4°C. The relationship between El Niño strength and impact on rainfall is however not straightforward, as there are also other factors affecting local and regional rainfall patterns.

5Rainfall in May 2014 has so far been above average for most parts of Singapore. However, drier weather can be expected from the second week of June 2014 with the onset of the Southwest Monsoon. For the next four months (June-September 2014), rainfall is expected to be below average for most parts of Singapore, and average daily temperature is expected to be above average.

6Prolonged drier and warmer conditions during an El Niño will increase the risk of the occurrence of transboundary smoke haze from land and forest fires in the region. Depending on various factors such as wind direction and locations of hotspots in the fire-prone areas, Singapore could be affected by transboundary smoke haze during this period.

7MSS 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.

8In anticipation of the onset of drier weather, the Inter-Agency Haze Task Force (HTF) has already been activated and is co-ordinating their respective action plans in preparation for haze. Forecasts and advisories will take into account the new PSI system, as well as the revised Ministry of Health (MOH)’s health advisories and Ministry of Manpower (MOM)’s workplace guidelines. The public can access the latest issued advisories at the NEA website (www.nea.gov.sg), the haze microsite (www.haze.gov.sg), or follow NEA on NEA Facebook (www.facebook.com/NEASingapore) and NEA Twitter (@NEAsg).

9Reservoir stock levels will be impacted by drier weather and lower rainfall. In response, PUB will have to ramp up its production of NEWater and desalinated water to maintain reservoir stock and ensure water availability. To prepare for the drier months ahead, PUB strongly urges the community and businesses to continue to conserve water, and play our part to stretch our water resources.

Table 1: Long-term temperature and rainfall statistics of Changi Climate Station

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Singapore, 16 March 2014 – Widespread, heavy showers in the late morning and afternoon today has ended the 27-day dry spell in Singapore that started on 17 February 2014. An earlier dry spell between 13 January and 8 February 2014 also lasted 27 days.

2The periods of showers that started at 9:40am today were due to an equatorial band of extensive rain clouds in the southern part of the South China Sea, brought in to Singapore and the surrounding region by strong, deep easterly winds. The showers were heaviest in the eastern and southern parts of the island, which received the least rainfall during the dry spell. All except one of the Meteorological Service Singapore’s 64 rainfall stations recorded rainfall above 1.0mm. As at 6.30pm today, the highest rainfall total is 52.6mm at Changi. 19 other stations in the east, south and central areas recorded rainfall totals ranging from 31.0mm to 51.8mm. The highest rainfall recorded in an hour is 33.2mm (between 12:35pm and 1:35pm) at Sentosa.

3For the next two days, thundery showers are forecast in the late morning and afternoon. With the easing of the dry phase of the Northeast Monsoon, more rainfall can be expected over the next fortnight as the Northeast Monsoon transitions to the Inter-monsoon period expected in the last week of March 2014.

4For updates, visit our NEA website (www.nea.gov.sg), haze microsite (www.haze.gov.sg) or follow us on NEA Facebook www.facebook.com/NEASingapore) and NEA Twitter (@NEAsg).

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Singapore, 15 March 2014 – Singapore can expect some rainfall in the coming days with the easing of the dry phase of the Northeast Monsoon. The rain will bring some respite to the current prolonged dry spell which started in mid-January 2014.

2Occasional brief showers this afternoon mostly affected the eastern and central parts of Singapore. As at 5pm today, the highest rainfall recorded was 3.8mm at Scotts Road. The rainfall this afternoon was not widespread and heavy enough to break the current dry spell. Passing showers in the afternoon are forecast for tomorrow and thundery showers in the afternoon for Monday.

3In the first 14 days of March 2014, the highest daily rainfall total for March 2014 is 15.2mm recorded at Tuas on 3 March 2014, and the total rainfall for March 2014 is 18.6mm recorded at Tuas. During this period, brief afternoon showers affected a few areas in western Singapore on some days. Other parts of the island received little or no rain. The days were also warmer and more windy. The daily maximum temperature in some parts of the island exceeded 33.0 degrees Celsius on most days. As of 14 March 2014, the Changi climate station recorded an average daily maximum temperature of 33.0 degrees Celsius, which is warmer than the long-term daily average of 31.6 degrees Celsius for March. The average daily wind speed of 13.2km/h recorded at the station is also significantly higher than the long-term average of 5.5km/h for March.

4The Northeast Monsoon is expected to transition to the inter-monsoon period in the last week of March 2014. The winds over Singapore and the surrounding region are expected to weaken and become variable in direction. Singapore may be affected by transboundary haze if hotspot activities in Sumatra and Peninsular Malaysia persist, and the prevailing winds temporarily turn to blow any haze toward us. The inter-monsoon period typically lasts from late March to May.

5Despite an expected increase in rainfall during the second half of March 2014, rainfall total for March 2014 is likely to be below the long-term average of 185.9 mm.

6For updates, visit our NEA website (www.nea.gov.sg), haze microsite (www.haze.gov.sg) or follow us on NEA Facebook www.facebook.com/NEASingapore) and NEA Twitter (@NEAsg).

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JOINT ADVISORY BETWEEN NEA AND PUB

Singapore, 4 March 2014 – The prolonged dry weather affecting Singapore since mid-January 2014 has set a new record for the driest month since 1869. At the Changi climate station, the rainfall total recorded in February 2014 was 0.2mm, breaking the previous record of 6.3 mm in February 2010. During the month, there were only seven days of short duration showers between 7 and 19 February 2014, mainly in the western parts of Singapore. The rainfall totals across 64 rainfall stations range from 45% to 100% below the long-term average of 161.0mm for February. About half the stations, mostly in the southern and eastern areas, recorded monthly rainfall totals below 10.0mm.

2Apart from being the driest month ever, February 2014 is the most windy month in the last 30 years. At the Changi climate station, the average daily wind speed of 13.3 km/hr recorded in February 2014 exceeds the previous high of 12.5 km/hr in January 1985. The prolonged dry conditions have also set a new record for the lowest average daily relative humidity of 74.5%. The previous record low for February and any month of the year was 76.9% (February 1968) and 74.6% (June 2013) respectively. The weather statistics for February 2014 are summarised in Table 1.

3The last day of significant rainfall was on 16 February 2014, when between 0.2 and 29.0 mm was recorded in various parts of the island. Since then, there has been little or no rainfall, with Singapore entering another period of dry spell on 17 February 2014. This follows the 27-day long dry spell between 13 January and 8 February 2014. The highest recorded rainfall total since 17 February 2014 was 19.2mm at Lim Chu Kang Road. The brief showers yesterday which brought limited rainfall of between 0.2 and 15.2 mm in some parts of western Singapore were not widespread enough to break the current dry spell.

4The dry weather affecting Singapore and the surrounding region is expected to persist in the first half of March 2014. There may be localised showers in the afternoon on a few days, and rainfall is expected to be well below average. Generally fair and warm conditions are forecast for Singapore. The prevailing northeasterly winds are also forecast to remain steady over this period. With the expected onset of the Inter-Monsoon in the second half of March 2014, the winds in the region will turn light and variable in direction. Increased rainfall can be expected in the later part of the month.

5With the dry weather expected to continue, PUB, the national water agency (PUB) has started a public campaign to urge everyone to conserve water. For example PUB has sent circulars to 25,000 non-domestic customers – including the town councils, Management Corporation Strata Title (MCSTs), commercial and industrial buildings, government buildings and schools – to advise them to make adjustments and embark on water-saving measures. Measures like cutting down the washing of cars and irrigation of plants, as well as switching off water features/fountains will help reduce water usage.

6Wafer fabrication plant, Systems on Silicon Manufacturing Company Pte Ltd (SSMC) has cut down on the irrigation of plants and installed all taps in the toilets with water thimbles. “Collectively as a company, I am glad that our Water Efficient Building management has prepared us well to cope with this dry season. In a dry spell situation like now, we are motivated in putting even more efforts to conserve water. At our facility, watering of trees and plants are done in a sparing manner. All our taps in toilet are installed with water thimbles. Individually, on personal level, we also we encourage our staff to do less frequent car wash, use water wisely at home,” said Jagadish CV, CEO of SSMC.

7At home, we can also save water by taking showers under five minutes, washing clothes on a full load and reusing water for non-potable uses. They can also cut down on non-essential water consumption like the washing of cars and irrigation of plants. The amount of water we save will help stretch our limited water resources longer.

8The National Environment Agency (NEA) and PUB will continue to monitor the situation and provide updates as necessary. For updates, visit the NEA website (www.nea.gov.sg) or follow us on NEA Facebook (www.facebook.com/NEASingapore) and NEA Twitter (@NEAsg). For information on water-saving tips, visit http://www.pub.gov.sg/conserve/Pages/default.aspx and www.facebook.com/PUBsg.

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Singapore, 10 February 2014 – Various parts of Singapore received daily rainfall ranging from 0.2mm to 50.6mm over the weekend (8-9 February 2014), following a dry spell that started in mid January 2014. Meteorological Service Singapore reports that all 64 rainfall stations across the island recorded no rainfall from 16 January to 7 February 2014, except for 0.2mm of rainfall at Jurong on 2 February 2014.

2On Saturday (8 February 2014), showers fell mainly over northern and eastern Singapore between 4pm and 6:30pm. Rainfall of at least 1mm was recorded at 15 stations, with Woodlands receiving the highest daily rainfall total of 50.6mm.

3On Sunday (9 February 2014), showers fell mostly over the western and central parts of the island in the late afternoon. Rainfall of at least 1mm was recorded at 17 stations, with the Bukit Timah area receiving the highest daily rainfall total of 21.8mm. The weekend showers were due to localised wind convergence over the island.

4While the rain over the weekend provided some relief from the dry spell*, Singapore and the surrounding region are still in the dry phase of the prevailing Northeast Monsoon. As of 9 February 2014, 33 stations including the Changi climate station recorded daily rainfall total of less than 1mm since 16 January 2014.

5For this week, showers mostly in the afternoon can be expected. However a strengthening of winds over the South China Sea could bring drier conditions to Singapore on a few days during the week.

* A dry spell is defined as a period of at least 15 consecutive days with daily rainfall total of less than 1mm in many parts of the island.

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Dry conditions to persist for at least the next one to two weeks

Singapore, 29 January 2014 – Singapore is currently in the dry phase of the Northeast Monsoon season, typically characterised by drier and cooler weather and generally windy conditions. The onset of this dry phase is earlier than usual this year, leading to fewer rain days and significantly lower rainfall this month. The last few weeks have also been marked by a spell of cooler than normal minimum temperatures.

2The rainfall total for January (1 to 28 Jan 2014) ranged from 20 to 125 mm (45-90% below the long-term average) across the island. At the Changi climate station, 75.4mm of rainfall and five rain days were recorded over this period, compared to the long-term average rainfall of 242.3mm and 15 rain days respectively for January^[1]. The last recorded rainfall was 0.8mm in Jurong on 16 January 2014.

3Since 14 January 2014, daily minimum temperatures of between 21 and 22 degrees Celsius were recorded in various parts of the island. The cooler than normal temperatures are due to a surge of cold winds from a high pressure system over China, blowing towards Singapore and the region. Singapore last experienced a similar spell of cool minimum temperatures during the Northeast Monsoon in early 2009.

4In the coming days, the current cool daily minimum temperatures are expected to increase slightly to the long term average value of around 23.5 degrees Celsius for January and February. However, the current dry and occasionally windy conditions are forecast to persist for at least the next one to two weeks. During this period, slight haze may occur under light wind conditions on a few mornings.

5For the Lunar New Year holiday period, the weather is expected to be fair and occasionally windy, with the daily temperature ranging between 23 and 31 degrees Celsius.