Expect warm and occasionally windy conditions with passing showers on 3 – 4 days as we step into the first week of the new year. Warm and windy weather likely to ease with more showers expected towards the end of the 1st week of Jan 2019.
Singapore, 31 December 2018 – The prevailing Northeast Monsoon in the region is expected to persist into January 2019 with the high pressure system over the northern Asian continent strengthening over the next few days. The low level winds are forecast to blow mainly from the northwest in the first week before shifting to blow from the northeast towards the second week of January 2019.
2 In the first fortnight of January 2019, Singapore is expected to experience short-duration moderate to heavy thundery showers mainly in the afternoon on six to eight days. In the first week of the month, a tropical storm is forecast to move into the South China Sea and bring a strengthening of northwesterly to northerly winds over Singapore and the surrounding region. Coupled with slightly drier atmospheric conditions, warm and occasionally windy conditions with passing showers can be expected on three to four days that week.
3 The daily temperatures in the first fortnight of January 2019 are expected to range between 24°C and 33°C on most days. On days when there is little or no rainfall, warm conditions with maximum temperatures of around 34°C can be expected.
4 The warm and windy weather is likely to ease with more showers expected towards the end of the first week of January 2019. Overall, rainfall for the first fortnight of January 2019 is forecast to be near-normal.
REVIEW (1 – 30 December 2018)
6 Northeast Monsoon conditions prevailed in December 2018, with low level winds blowing mainly from the north or northeast in the first three weeks of the month. Under the influence of a low pressure system in the South China Sea in the last week of December 2018, the low level winds over Singapore and the surrounding vicinity turned to blow from the west.
7 Singapore and the surrounding region experienced wet weather conditions in the first three weeks of the month due to the close proximity of the monsoon rain band to the equatorial South China Sea region. Thundery showers fell over many parts of the island in the afternoon on most days during this period, occasionally stretching into the evening. The highest daily total rainfall of 97.3 mm was recorded on 20 December 2018 at Yio Chu Kang. The intense thunderstorms, which developed due to strong solar heating, brought gusty winds that felled two trees at Sembawang Park. A maximum wind gust of 63.0 km/h was recorded at Seletar on that day. In addition, a waterspout developed from intense thunderstorms over the sea areas southeast of East Coast Park, which was sighted from various locations in Singapore in the late afternoon.
8 The last week of December 2018 saw a change in winds to blow more from the west and showers affected mainly the western and southern parts of Singapore on a few mornings. A Sumatra squall affected Singapore in the early hours and predawn hours on 26 December 2018, bringing thundery showers and gusty winds to parts of the island. The strongest wind gust of 77.4 km/h was recorded at Pasir Panjang on that day. In the last week of 2018, Singapore experienced drier and warmer conditions due to strong solar heating and low rainfall under the stable atmospheric conditions over our region, arising from a low pressure system in the South China Sea that drew some rainclouds away from our region.
9 During the month, Singapore’s daily maximum temperature ranged between 32.5°C and 34.0°C. The highest daily maximum temperature of 34.7°C was recorded on 23 December 2018 in the Newton area. The daily minimum temperature mainly ranged between 23.0°C and 24.5°C. At the Changi climate station, the mean monthly temperature for December 2018 (as of 30 December) is 27.6°C. This is 1.2°C higher than the long term average temperature of 26.4 deg C for December, and slightly warmer than the December in the last two years.
10 About two thirds of the island received below normal rainfall in December 2018. The lowest rainfall of 126.2mm (58% below average) was recorded in the Pasir Ris area. Rainfall was highest around the Jurong area where 357.4mm (33% above average) was recorded.
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 monthly mean daily minimum temperature||23.0 °C (1981,1983)|
|Highest monthly rainfall||765.9 mm (2006)|
|Lowest monthly rainfall||62.9 mm (1988)|