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Expect Sumatra squalls and slight haze on a few days

Advisory

Singapore, 17 August 2015 – The prevailing Southwest Monsoon conditions are expected to persist for the rest of August 2015, and the low level winds are forecast to blow from the southeast or southwest.

2.   For the second half of August 2015, some warm days with maximum day-time temperatures of 34 degrees Celsius can be expected in the afternoon. Short-duration thundery showers due to strong solar heating of land areas are likely on three to five days, mostly in the late morning and early afternoon. In addition, thundery showers with gusty winds due to Sumatra squalls can be expected on one to two days in the pre-dawn and morning.

3.   As periods of consecutive dry days are common in the region during the Southwest Monsoon season, Singapore could experience slightly hazy conditions on a few days.

4.   The rainfall for the August 2015 is expected to be slightly below normal.

Review of 1 – 16 August 2015

5.   Southwest Monsoon conditions prevailed during the first fortnight of August 2015 with the low level winds blowing predominantly from the southeast or southwest.

6.   During the review period, there were a few warm days with the daily maximum temperature of around 34 degrees Celsius, as well as some wet days where the daily minimum temperatures fell to between 22 and 23 degrees Celsius. On several days in the first fortnight of August 2015, Singapore experienced moderate to heavy thundery showers with gusty winds due to the passage of Sumatra squalls and strong convergence of winds over Singapore and the surrounding vicinity. In particular, the thundery showers on 12 August 2015 brought heavy rainfall over the north-eastern part of the island where the highest total rainfall of 71.6mm was recorded over Pulau Ubin.

7.   During the first fortnight of August 2015, the southern half of Singapore received above average rainfall. The highest rainfall of 150 mm to 180 mm (65% to 90% above average) was recorded over the south-western and eastern parts of the island around Boon Lay and Tampines respectively. The lowest rainfall of 50 mm to 70 mm (25% to 50% below average) was recorded over the northern and central parts of Singapore around Sembawang and Bishan respectively.

STATISTICS FOR AUGUST since 1869 (CLIMATE STATION)

Average rainfall for the month — 175.4 mm
Highest rainfall ever recorded — 526.8 mm (1878)
Lowest rainfall ever recorded — 18 mm (1888)
Average number of rain days — 14
Average daily maximum temperature — 30.9 degrees Celsius
Average daily minimum temperature — 24.5 degrees Celsius

– End –

Dry and warm weather in the second week of August

Advisory

Singapore, 31 July 2015 – Southwest Monsoon conditions are forecast to prevail during the next fortnight with low level winds blowing predominantly from southeast or south-southwest.

2.   In the first fortnight of August 2015, short-duration thundery showers due to strong solar heating of land areas are likely on 4 to 6 days, mostly in the late morning and early afternoon. In addition, thundery showers with gusty winds due to Sumatra squalls can be expected on 2 or 3 days in the morning. Most of the thundery showers are expected in the first week of August 2015 while dry and warm conditions with maximum temperatures of around 34 degrees Celsius can be expected in the latter half of the fortnight. In particular, for the Jubilee weekend, short-duration thundery showers are forecast in the late morning and early afternoon.

3.   Slightly hazy conditions can be expected on a few days, in particular in the early morning, due to the accumulation of particulate matter under light wind conditions.

4.   The rainfall for the first fortnight of August 2015 is expected to be near-normal.

Review of 1 – 30 July 2015

5.   Southwest-Monsoon conditions prevailed in July 2015. During the period, the low level winds blew from the southeast or south-southwest.

6.   Singapore experienced warm conditions in July 2015 where maximum day-time temperatures of between 34 and 35 degrees Celsius were recorded on some days. The daily minimum temperature recorded during the month ranged from 22 to 28 degrees Celsius. Thundery showers fell over the island on several days mostly in the late morning and early afternoon. In addition, thundery showers with gusty winds affected Singapore on a few mornings due to the passage of a Sumatra squall. The highest daily total rainfall recorded for the month was 71mm on 17 July 2015 around Lim Chu Kang.

7.   In July 2015, most parts of Singapore received below-average rainfall. The lowest rainfall of 35mm and 55mm (65 to 80% below average) was recorded over the southwestern part of Singapore around Jurong. Rainfall was highest over the northwestern part of the island around Woodlands and Lim Chu Kang respectively, where 164mm to 185mm (0 to 25% above average) of rain was recorded.

STATISTICS FOR AUGUST since 1869 (CLIMATE STATION)

Average rainfall for the month — 175.4 mm
Highest rainfall ever recorded — 526.8 mm (1878)
Lowest rainfall ever recorded — 18 mm (1888)
Average number of rain days — 14
Average daily maximum temperature — 30.9 degrees Celsius
Average daily minimum temperature — 24.5 degrees Celsius

– End –

Below-normal rainfall forecast for the month

Advisory

Singapore, 15 July 2015 – Southwest Monsoon conditions are forecast to prevail during the next fortnight, with surface winds blowing predominately from the southeast or southwest.

2.     In the second fortnight of July 2015, short-duration thundery showers due to strong solar heating of land areas are forecast on 4 to 6 days in the late morning and afternoon. Daily maximum temperatures of up to about 33 degrees Celsius are forecast on some days during this period. In addition, thundery showers with gusty winds due to Sumatra squalls are likely on 1 to 2 days in the pre-dawn and morning. Slightly hazy conditions can also be expected on a few days, in particular in the early morning, due to the accumulation of particulate matter under light wind conditions.

3.    Rainfall for July 2015 is expected to be below-normal.

Review of 1 – 14 July 2015

4.    Southwest Monsoon conditions prevailed during the first fortnight of July 2015, with the surface winds blowing predominantly from the south-southeast or southwest.

5.    In the first fortnight of July 2015, there were a few warm days with the daily maximum temperature reaching up to 34.6 degrees Celsius, as well as some wet days where the daily minimum temperatures fell to between 22 and 23 degree Celsius. On several days in the second week of July 2015, Singapore experienced thundery showers with gusty winds in the morning due to the passage of Sumatra squalls. On 10 July 2015, Singapore was briefly affected by slight haze due to a change in the prevailing winds to blow from the southwest which could have brought in some smoke haze from fires in the nearby region.

6.    For the first half of July 2015, the southern and western parts of Singapore received below average rainfall. The highest rainfall of 110 mm and 130 mm (50% to 75% above average) were recorded over the central and eastern parts of the island around Lower Peirce Reservoir and Changi respectively. The lowest rainfall of 25 mm to 45 mm (40% to 65% below average) was recorded over the western parts of Singapore around Jurong.

STATISTICS FOR JULY since 1869 (CLIMATE STATION)

Average rainfall for the month — 158.6 mm
Highest rainfall ever recorded — 527.3 mm (1890)
Lowest rainfall ever recorded — 18.6 mm (1997)
Average number of rain days — 13
Average daily maximum temperature — 30.9 degrees Celsius
Average daily minimum temperature — 24.6 degrees Celsius

– End –

Expected few mornings with slight haze and Sumatra squalls

Advisory

Singapore, 1 July 2015 – Southwest Monsoon conditions are forecast to prevail during the next fortnight with low level winds blowing predominately from southeast or south-southwest.

2.     In the first half of July 2015, several warm days with maximum temperatures around 34 degrees Celsius can be expected in the afternoon. Short-duration thundery showers due to strong solar heating of land areas are likely on 3 to 5 days, mostly in the late morning and early afternoon. In addition, thundery showers with gusty winds due to Sumatra squalls can be expected on 1 or 2 days in the morning.

3.     Slightly hazy conditions can be expected on a few days, in particular in the early morning, due to the accumulation of particulate matter under light wind conditions.

4.     Based on long-term statistics, July has the lowest average monthly rainfall in the year. The rainfall for the first fortnight of July 2015 is likely to be below-normal.

Review of 1 – 30 June 2015

5.     Southwest-Monsoon conditions prevailed in June 2015. During the period, the low level winds were blown from the southeast or south-southwest.

6.     Dry and warm conditions were experienced on most days in June 2015. There were thundery showers over the island on several days in the late morning and early afternoon, and the highest daily total rainfall recorded for the month was 69mm on 16 June 2015 in the Jurong area.

7.     In June 2015, most parts of Singapore received below-average rainfall. The highest rainfall of 160mm and 191mm (0 to 20% above average) was recorded over the western part of the island around Jurong. Rainfall was lowest over the central and eastern parts of Singapore around Whampoa and Marine Parade respectively, where 25mm to 49mm (70 to 85% below average) of rain was recorded.

STATISTICS FOR JULY since 1869 (CLIMATE STATION)

Average rainfall for the month — 158.6 mm
Highest rainfall ever recorded — 527.3 mm (1890)
Lowest rainfall ever recorded — 18.6 mm (1997)
Average number of rain days — 13
Average daily maximum temperature — 30.9 degrees Celsius
Average daily minimum temperature — 24.6 degrees Celsius

– End –

Increased risk of hotspot activity and transboundary haze

Singapore, 26 June 2015 – Meteorological Service Singapore (MSS) is forecasting that Singapore and the surrounding region can expect a drier and warmer than usual Southwest Monsoon season[1] (June – September/early October) this year. This is partly due to the prevailing moderate El Niño[2] conditions in the equatorial Pacific Ocean, which are likely to further develop in the months ahead.

2         With fewer rain days experienced this month, the total rainfall for June 2015 (as at 25 June 2015) recorded at the Changi climate station is 38% below the long-term average. Warmer days and nights have also been experienced in recent days. The average daily maximum and minimum temperatures for June 2015 (as at 25 June 2015) are 31.9°C and 26.5°C, about 0.6°C and 1.7°C above the long-term average respectively .

3          Lower than usual rainfall is expected to persist for Singapore in the next few months. For July 2015 the total monthly rainfall is forecast to be 15-45% below average. The long-term rainfall and temperature statistics for July to September at the Changi climate station are shown in Table 1.

Table 1: Long-term temperature and rainfall statistics for July-September

Impact of El Niño on Singapore

4          Most models from the major global climate centres project a high likelihood that the tropical Pacific sea surface temperatures would continue to warm over the coming months and possibly reach strong El Niño levels. During the 1997 El Niño which is the strongest on record, Singapore experienced a sharp 53% reduction in June-September rainfall. In the last occurrence of a moderate El Niño in 2009, Singapore’s rainfall total over the June-September period was about 20% below the long-term average. The average daily temperature for the same period in 2009 was 1.1°C higher than the long-term average of 27.4°C. The relationship between the strength of the El Niño and the impact on rainfall is however not straightforward, as there are also other factors affecting local and regional rainfall patterns.

Risk of Transboundary Haze

5          With the drier and warmer weather over the southern ASEAN region in the coming months, exacerbated by the prevailing El Niño, we may see an escalation of hotspot activities, particularly in the fire prone provinces in Sumatra and Kalimantan. This would increase the risk of occurrence of transboundary haze in the region. The impact of the smoke haze on Singapore is dependent on factors such as the proximity and extent of the fires, the strength and direction of the prevailing winds, and the incidence and amount of rain.

6          In recent days, sporadic hotspot activities with localised smoke plumes have been observed in Sumatra. In addition, drier and warmer weather conditions have prevailed over Singapore and the surrounding region, indicating the start of the traditional dry season in the southern ASEAN region.

7          MSS will continue to closely monitor the regional weather and haze situation as well as the development of the El Niño, and provide updates when necessary. Updates on haze information and the El Niño are available in the MSS website at

• https://www.weather.gov.sg/warning-haze-satellite-image/
• https://www.weather.gov.sg/climate-el-la/

Haze Preparedness

8          In anticipation of the onset of drier weather, the Inter-Agency Haze Task Force (HTF) is co-ordinating the agencies’ respective action plans in preparation for haze. NEA’s haze forecasts and advisories will take into account the Ministry of Health (MOH)’s health advisories and Ministry of Manpower (MOM)’s workplace guidelines. The public can access NEA’s 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).

PUB’s preparedness

9          Drier weather and lower rainfall will affect reservoir stock levels. To prepare for the drier months ahead, PUB strongly urges the community and businesses to continue to conserve precious water.

~End~

[1] Southwest Monsoon season is characterised by prevailing winds that blow predominately from the southeast or southwest. The Southwest Monsoon months are generally the drier months of the year.

[2] The El Niño is known to disrupt normal weather patterns around the world, and in the ASEAN region, the El Niño could lead to prolonged drier and warmer weather over large parts of Southeast Asia. Singapore would normally experience drier and warmer conditions during moderate to strong El Niño events, especially during the Southwest Monsoon period. At other times outside of these months, the impact of El Niño on local rainfall is not as significant.

Sumatra squalls and slightly hazy conditions also expected on few mornings

Advisory

Singapore, 16 June 2015 – Southwest Monsoon conditions are expected to persist for rest of June 2015, and the low level winds are forecast to blow predominantly from the southeast or southwest.

2As compared to the first half of June 2015, the second fortnight of June 2015 could experience fewer rain days. Short-duration thundery showers due to strong solar heating of land areas are likely on three to five days, mostly in the late morning and early afternoon. In addition, thundery showers with gusty winds due to ‘Sumatra’ squalls can be expected on one or two days in the pre-dawn and morning. On some days, maximum day-time temperatures of 34 degrees Celsius and warm nights can be expected.

3Slightly hazy conditions can be expected on a few days, in particular in the early morning due to the accumulation of particulate matter under light wind conditions.

4Rainfall for June 2015 is likely to be below normal.

Review of 1 – 15 June 2015

5Southwest Monsoon conditions prevailed in the first fortnight of June 2015 with low level winds blowing predominantly from the southeast or southwest. In the first week of June 2015, Singapore experienced a few warm days, in particular over the north-western part of the island, where the maximum daily temperature recorded was around 35 degrees Celsius.

6During the review period, Singapore experienced thundery showers on several days in the late morning and afternoon due to strong solar heating of land areas and convergence of winds. The highest total rainfall of 68.4mm was recorded on 8 June 2015 over Jurong. On 12 June 2015, moderate to heavy thundery showers affected many parts of the island in the afternoon, and the highest total rainfall recorded that day was 65mm over Mandai.

7Between 1 and 15 June 2015, rainfall was above average in the western parts of Singapore, and below average in the central and eastern parts of the island. The highest rainfall of 140mm and 170mm (70% to 110% above average) was recorded around Jurong, and the lowest rainfall of 20mm and 40mm (50% to 75% below average) were recorded around MacRitchie and East Coast areas.

STATISTICS FOR JUNE since 1869 (CLIMATE STATION)

Average rainfall for the month — 160.4 mm
Highest rainfall ever recorded — 378.7 mm (1954)
Lowest rainfall ever recorded — 21.8 mm (2009)
Average number of rain days — 13
Average daily maximum temperature — 31.3 degrees Celsius
Average daily minimum temperature — 24.8 degrees Celsius

– End –

The public can view if it is raining over the 28^th SEA Games 2015 venues by selecting the check box “SEA Games 2015 venues” in the Rain Areas page (as shown in the image below)

Sumatra squalls and slightly hazy conditions also expected on few mornings

Advisory

Singapore, 2 June 2015 – During the next fortnight, Southwest Monsoon conditions are forecast to set in and low level winds are expected to blow from southeast or south-southwest.

2In the first half of June, a few warm days with maximum temperatures around 34 degrees Celsius can be expected in the afternoon. In addition, short-duration thundery showers due to strong solar heating of land areas are likely on five to seven days, mostly in the late morning and early afternoon. Thundery showers with gusty winds due to Sumatra squalls can be expected on one to two days in the pre-dawn and morning.

3Slightly hazy conditions can be expected on a few days, in particular in the early morning, due to the accumulation of particulate matter under light wind conditions.

4Rainfall for the first fortnight of June 2015 is likely to be near-normal.

Review of 1 – 31 May 2015

5Inter-Monsoon conditions prevailed in May 2015. During the period, the low level winds were light and variable in direction for most parts of the month, and occasionally blew from the southeast or south-southwest in the last week of May 2015.

6Singapore experienced wet weather conditions on most days in May 2015. The thundery showers fell mainly in the late morning and afternoon with the highest total rainfall of 119.6mm recorded on 3 May 2015 over Bukit Panjang area. In addition, on 23 May 2015, moderate to heavy thundery showers due to a Sumatra squall affected many areas of Singapore in the pre-dawn and morning.

7In May 2015, most parts of Singapore received near-average rainfall. The highest rainfall of 352mm and 368mm (80% to 115% above average) were recorded over the western and northern parts of the island around Choa Chu Kang and Woodlands respectively. The lowest rainfall of 59mm and 67mm (50% to 80% below average) were recorded over the eastern and south-western parts of the island around Changi and Tuas respectively.

STATISTICS FOR JUNE since 1869 (CLIMATE STATION)

Average rainfall for the month — 160.4 mm
Highest rainfall ever recorded — 378.7 mm (1954)
Lowest rainfall ever recorded — 21.8 mm (2009)
Average number of rain days — 13
Average daily maximum temperature — 31.3 degrees Celsius
Average daily minimum temperature — 24.8 degrees Celsius

– End –

Comprehensive weather and climate information packaged in one easy-to-use website

Singapore, 20 May 2015 – Need to know where in Singapore there is currently rain? Or what the weather will be in the next two hours where you are? With the new weather information website launched today by Meteorological Service Singapore (MSS), the public can now access more comprehensive real-time and past weather information of Singapore. The one-stop website (https://www.weather.gov.sg) provides authoritative weather forecasts, warnings and advisories of heavy rain, smoke haze and geological hazards, as well as long-term climate statistics of Singapore.

Enhancing Current Weather Situation Awareness

2          One key feature of the new website is a map display of real-time observations of temperature, rainfall, humidity and surface wind at various locations across the island. These weather elements are measured continuously by MSS’ island-wide network of over 60 automatic weather stations. The observations are updated on the website at five minute intervals, giving an indication of where the currently warmest, wettest or windiest parts of the island are. Users can also view graphs that display the trends of temperature and other elements at selected locations over the course of the day.

3          Those engaging in outdoor activities can also visit the website for the latest information on where rain is falling over Singapore and our surrounding region, a few hundred kilometres away. They can also access information on lightning detected over the island, and get lightning alerts for pre-selected locations.

Better Planning and Preparedness with Forecasts and Warnings

4          Forecasts of the weather over Singapore, ranging from hours to days ahead, are also available on the website to help users make better informed decisions. For a general weather outlook further ahead, one can refer to the fortnightly outlook and updates on the monsoon season and the El Nino/La Nina.

5          Apart from the regular weather forecasts, the website provides heavy rain warnings for Singapore and regular updates and advisories on smoke haze, tropical cyclones, earthquakes, tsunami and volcanic eruptions affecting the region.

Knowing Past Weather History

6          Another key feature of the website is a comprehensive database of historical climatological records of Singapore since 1980. The database contains daily readings of rainfall, temperature and wind at various locations across the island, which can be downloaded if needed. Such data will be of particular interest to people who wish to know the weather conditions on a specific day in the past, or to carry out analysis of past weather data. Also included are Singapore’s past climate trends and historical extremes of various weather elements.

7          The new website includes extensive educational content which serves as a resource for those who are keen to learn more about our weather and climate. Photography enthusiasts are also invited to contribute photos they have taken of interesting weather phenomena observed in Singapore. Selected photos will be featured on the website. To submit your photos, email them to NEA_MSS_Engage@nea.gov.sg.

Slight haze also expected on a few days in the early mornings

Advisory

Singapore, 15 May 2015 – During the next fortnight, Inter-Monsoon conditions are expected to prevail. During the period, the prevailing light and variable low level winds are forecast to gradually turn to blow from the southeast or south-southwest.

2For the fortnight, Singapore can expect 4 or 5 days of short-duration thundery showers in the late morning and early afternoon. In addition, 1 or 2 days of thundery showers with gusty winds due to Sumatra squalls are likely in the pre-dawn and morning. Slightly hazy conditions can be expected on a few days, in particular in the early morning, due to accumulation of particulate matter under light wind conditions.

3Rainfall for May 2015 is likely to be near-normal.

Review of 1 – 14 May 2015

4Inter-Monsoon conditions prevailed in first fortnight of May 2015. During the period, the prevailing low level winds were generally light and variable in direction

5Singapore experienced wet weather conditions on most days in the first fortnight of the month with thundery showers occurring mostly in the afternoon. On 3 May 2015, moderate to heavy thundery showers affected many areas of Singapore in the afternoon and evening due to the convergence of winds and strong daytime heating of land areas. The highest total rainfall recorded on 3 May 2015 was 119.6mm over the Bukit Panjang area.

6Approximately two thirds of Singapore received above normal rainfall in the first half of May 2015. The western part of the island around Chua Chu Kang and Nanyang Avenue received the highest rainfall of 164mm to 210mm (110% to 150% above average). The lowest rainfall of 11mm to 24mm (50% to 90% below average) was recorded over the eastern part of the island around Changi.

STATISTICS FOR MAY since 1869 (CLIMATE STATION)

Average rainfall for the month — 172.1 mm
Highest rainfall ever recorded — 386.6 mm (1892)
Lowest rainfall ever recorded — 41.6 mm (1997)
Average number of rain days — 15
Average daily maximum temperature — 31.6 degrees Celsius
Average daily minimum temperature — 24.8 degrees Celsius

– End –