Warm weather expected to continue into May, thundery showers on most afternoons: Met Service
SINGAPORE: The warm and wet weather in April is expected to continue into the first fortnight of May, with showers expected on most days, said the Singapore Meteorological Service in its fortnightly outlook on Friday (Apr 30).
The prevailing inter-monsoon conditions over Singapore expected to persist into May. With the presence of the monsoon rain band close to the equatorial Southeast Asia region, showers are expected on most days in the first fortnight of next month.
In the first half of May, the low-level winds are forecast to be light and variable in direction. They may strengthen to blow from south-west or wet on some days.
Short-duration thunder showers with frequent lightning are expected in the afternoons over parts of Singapore on most days in the first fortnight of May.
"This is due to strong daytime heating of land areas or coupled with convergence of winds over Singapore and the surrounding vicinity," said the Met Service, adding that showers may extend into the evenings on a few days.
Convergence of low-level winds blowing from the south-west and west may trigger the development of Sumatra squalls over the Strait of Malacca in the first fortnight of May.
READ: Commentary: 2021 has already seen the wettest and driest months in decades. Is Singapore prepared for more?
"The eastward passage of the squall toward the South China Sea is expected to bring widespread thundery showers and gusty winds over Singapore on a few days between the predawn hours and morning," said the Met Service.
Overall, rainfall in the first half of May is expected to be above average over most parts of Singapore.
Warm conditions are expected on most days in the coming fortnight, with the daily temperature forecast to range between 24 degrees Celsius and 34 degrees Celsius. The daily maximum temperature could reach about 35 degrees Celsius on a few days, particularly when there are few clouds in the sky.
Warm nights can also be expected, with nighttime temperatures of up to 28 degrees Celsius on a few days, mostly over the southern and eastern coastal areas of the island when prevailing winds from the east or southeast bring in warm and humid air from the seas.
REVIEW OF APRIL WEATHER
In its review of the last month, the Met Service said inter-monsoon conditions prevailed over Singapore and the surrounding region. In April, the prevailing winds were generally light and variable in direction.
"Under the influence of a few tropical storms over the Western Pacific Ocean, the prevailing winds strengthened and blew from the south-west or west on some days," it said.
On most days in April, thundery showers fell in the afternoon over many parts of Singapore due to strong daytime heating of land areas. The showers extended into the evening and night on a few of these days, due to large-scale convergence of winds in the surrounding region.
The influence of Typhoon Surigae over the Western Pacific Ocean triggered the development of a Sumatra squall over the Strait of Malacca in the morning on Apr 17.
The squall brought widespread thundery showers over Singapore between the late morning and afternoon. The rain was also the heaviest over the western and southern parts of the island with several rainfall stations recording more than 100mm of rain that afternoon.
The daily total rainfall of 170.6mm was recorded at Ulu Pandan on Apr 17. It was the highest rainfall recorded for April 2021, said the Met Service.
"It is also the record highest rainfall in a day for April since 1980, surpassing the previous record of 159.9mm set in 2007," it added.
April was generally warm, with the maximum temperature above 34 degrees Celsius on most days. There were 11 days where temperatures of 35 degrees Celsius or more were recorded.
The highest daily maximum temperature of 36.3 degrees Celsius was recorded at Ang Mo Kio on Apr 2.
Many parts of Singapore also recorded well above-average rainfall in April, said the Met Service. The rainfall anomaly was highest at Mandai at 110 per cent above average.