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Significant below-normal rainfall forecast for March 2016

Advisory

Singapore, 15 March 2016 – The prevailing Northeast Monsoon conditions are expected to gradually weaken over the next fortnight. The low level winds are forecast to blow predominantly from the northeast or northwest, and become light and variable in direction as the Northeast Monsoon transitions to inter-monsoon conditions in the later part of the month.

2. The next fortnight is expected to be drier and warmer than that experienced in the first fortnight of March 2016. During this period, the daily maximum temperatures are expected to range between 33°C and 34°C, and could reach a high of around 36°C on a few days. The mean monthly temperature for March 2016 is likely to be comparable to that for the warmest March on record (29.5°C in 1998).

3. The warmer conditions are due to the continuing influence of the El Nino and the presence of a dry and warm air mass over the region. The occurrence of the equinox[1] is another contributing factor to the warm temperatures during this time of the year.

4. Despite the drier conditions, short-duration thundery showers in the afternoon on 4 to 6 days can still be expected over parts of Singapore, due to strong solar heating of land areas and convergence of winds in the surrounding vicinity. The rainfall for March 2016 is expected to be significantly below-normal.

Review (1 – 14 March 2016)

5. During the review period, Northeast Monsoon conditions prevailed in the region with the low level winds over Singapore blowing predominantly from the northeast.

6. In the first week of March 2016, Singapore experienced occasionally windy conditions with short-duration thundery showers in the afternoon on some days. Dry and warm conditions were experienced in the second week of the month where the daily maximum temperature recorded was between 34.5°C and 35.0°C.

7. Almost all areas of Singapore received below average rainfall in the first half of March 2016. Rainfall was lowest over the eastern part of the island around Pasir Ris, where 4mm (95% below average) was recorded. The highest rainfall of 119mm (15% above average) was recorded over the southwest-central part of Singapore around Queenstown.

[1] An equinox occurs twice a year around 20 March and 22 September. During an equinox, with the sun directly overhead around noon, sunlight reaching the earth’s surface is most intense and contributes to higher daytime temperatures.

CLIMATE STATION STATISTICS FOR MARCH (Climatological reference period: 1981 – 2010)

Short-duration thundery showers on some days

Advisory

Singapore, 16 February 2016 – For the next fortnight, Northeast Monsoon conditions are forecast to persist with the low level winds blowing predominantly from the north or northeast. The prevailing wet phase of the Northeast Monsoon season is expected to gradually transition to the dry phase of the season around the last week of the month. The dry phase of the Northeast Monsoon season is characterised by drier weather and occasionally windy conditions.

2. For the rest of February 2016, localised short-duration thundery showers are expected on 5 to 6 days in the afternoon due to strong solar heating of land areas and convergence of winds in the surrounding vicinity. Rainfall for February 2016 is expected to be near average.

3. It is expected to be drier and warmer in the second half of February 2016 compared to the first two weeks of the month. The temperature for the next fortnight is forecast to range between 25°C and 34°C. The mean monthly temperature for February 2016 is likely to be warmer than the long-term mean of 27.1°C for February. February 2016 could rank among the top five warmest February since records started in 1929.

Review (1 – 15 February 2016)

4. Northeast Monsoon conditions prevailed during the first fortnight of February 2016 with the low level winds over the region blowing predominantly from the northeast. During the Chinese New Year period (7 – 10 February 2016), a monsoon surge brought occasional windy conditions and moderate to heavy rain to areas in the southern South China Sea region.

5. On 7 February 2016, the monsoon surge brought widespread moderate rain to Singapore. The rain occurred from around midnight to the early afternoon, and the highest total daily rainfall recorded was 46.8mm over the northwestern part of the island. For the next three days (8 to 10 February 2016), with a shift in the winds to blow from the north, Singapore experienced cool, cloudy and occasional windy conditions with brief periods of light to moderate rain. Most of the heavy rain as a result of the surge fell over the sea areas to the south of Singapore. Daily maximum temperatures of below 30°C were recorded in Singapore on consecutive days during the Chinese New Year period.

6. For the rest of the review period, Singapore experienced thundery showers mostly in the afternoons and evenings due to strong solar heating of land areas coupled with localised wind convergence. The showers were heaviest on 12 February 2016 where the highest total daily rainfall recorded was 60.2mm around Ang Mo Kio.

7. Most parts of Singapore received above average rainfall in the first half of February 2016. The highest rainfall 125mm (72% above average) was recorded over the northern part of Singapore around Woodlands. Rainfall was lowest over the eastern part of Singapore around Changi, where 41mm (28% below average) was recorded.

8. There were a few warm days during the review period where the highest daily maximum temperature recorded ranged from 33.8°C to 34°C. The lowest daily minimum temperature recorded on a few days was between 21.5°C and 23.5°C. Despite the cooler weather experienced between 7 and 10 February 2016, the mean daily minimum temperature in the first fortnight of February 2016 was 25.9°C which is significantly warmer than the long-term mean of 24.3°C. In addition, the mean daily temperature of 28°C is warmer than the long-term February climatology of 27.1°C.

CLIMATE STATION STATISTICS FOR FEBRUARY (Climatological reference period: 1981 – 2010)