Northeast Monsoon Conditions to Prevail in December 2016

Expect cool nights on a few days

Singapore, 1 December 2016 – In late November 2016, the low level winds that were light and variable in direction gradually strengthened and shifted to blow from the northeast or northwest. This signalled the start of the Northeast Monsoon season in the region which typically extends from December to March.

2      In the first fortnight of December 2016, the prevailing low level winds are forecast to blow predominantly from the northeast or northwest. With the expected presence of low pressure systems such as tropical storms in the region, the low level winds could shift to blow from the west or southwest on some days.

3      For the next two weeks, short-duration thundery showers, at times heavy, are expected in the afternoon and evening on five to six days. In addition, widespread thundery showers accompanied by gusty winds due to the occurrence of Sumatra squalls can be expected between the predawn and morning on one or two days. The rainfall for the first two weeks of December 2016 is forecast to be below normal.

4      During the outlook period, daily maximum temperatures of between 32°C and 33°C are expected on most days. On a few rainy days, the daily maximum temperature could reach a high of around 30°C, and the daily minimum temperature, in particular during the night, is expected to be cool and range between 22°C and 24°C.

5      For updates of the daily weather and haze forecast, please visit our MSS website (www.weather.gov.sg), NEA website (www.nea.gov.sg), the haze microsite (www.haze.gov.sg) or download the myENV app, MSS’ Weather@SG app.

Review: 1 – 30 November 2016

6      Inter-Monsoon conditions prevailed over Singapore and the surrounding region for most parts of November 2016 before the onset of the Northeast Monsoon season in late November 2016. The low level winds during the period were predominantly light and variable in direction.

7      Despite the wet weather conditions experienced in November 2016, there were some warm days where the highest daily maximum temperature recorded was between 33.6°C and 34.4°C. At the Changi climate station, the mean monthly temperature for November 2016 was 27.4°C, 0.4°C warmer than the long-term mean for November.

8      In November 2016, the thundery showers occurred mostly in the afternoon due to strong solar heating of land areas coupled with the convergence of winds over Singapore and the surrounding vicinity. On several days during the month, the occurrence of Sumatra squalls brought moderate to heavy thundery showers to many parts of Singapore in the pre-dawn hours and morning. The heaviest daily rainfall of 128mm was recorded on 14 November 2016 over Semakau Island while for the mainland Singapore, the highest rainfall recorded was 78.2mm over the Jurong area on 16 November 2016.

9      About half of Singapore received above normal rainfall in November 2016. The highest rainfall of 413.2mm (53% above average) was recorded around Paya Lebar area. Rainfall was lowest around Admiralty where 160.6mm (36% below average) was recorded.

FortnightRain_Anomaly_201611b

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

Mean daily maximum temperature 30.2 °C
Mean daily minimum temperature 24.0 °C
Mean monthly temperature 26.4 °C
Mean rainfall for the month 318.6 mm
Mean number of rain days 18
Highest monthly mean daily maximum temperature 31.3 °C (1997, 2002)
Lowest monthlymean daily minimum temperature 23.0 °C (1981,1983)
Highest monthly rainfall 765.9 mm (2006)
Lowest monthly rainfall 62.9 mm (1988)