SINGAPORE \u2013 The non-stop rain and sweater weather Singapore<\/p>\n experienced in early January 2025<\/p>\n <\/a> is unlikely to be repeated in the week ahead, as a monsoon surge is not expected between now and Jan 11, 2026, the weatherman told The Straits Times. <\/p>\n This comes as the Malaysian Meteorological Department in late December warned of a monsoon surge descending on the country in early January 2026, with over 1,000 people evacuated in Sarawak due to worsening floods. <\/p>\n A monsoon surge is a weather phenomenon that usually happens in Singapore during the wet phase of the north-east monsoon season, which is in December and January. <\/p>\n During this period, two to four surge events typically occur. Each episode can last a few days. <\/p>\n The phenomenon occurs when bursts of cold, dry air from wintry regions like Central Asia move over the warm waters of the South China Sea, picking up moisture. This brings extensive rainfall, strong winds and cooler temperatures to Singapore. <\/p>\n The first monsoon surge of 2025 on Jan 10 led to a nearly three-hour flood in Jalan Seaview in Mountbatten. The four-day downpour delayed and diverted flights, and hit business at the Chinese New Year bazaars.<\/p>\n The flash flood in the coastal area occurred because high tides of up to 2.8m coincided with the prolonged intense rain from the surge. The rain that fell over Jan 10 and 11 exceeded the month\u2019s average. <\/p>\n This week, high tides are also expected. ST checks on the National Environment Agency\u2019s website showed that tides are expected to exceed 3m in the afternoons, reaching 3.3m on a couple of days. Around noon on Jan 5, Sungei Buloh Wetland Reserve recorded a high tide of nearly 4m. <\/p>\n High spring tide close to the main hide of Sungei Buloh Wetland Reserve on Jan 5.<\/p>\n ST PHOTO: LIM YAOHUI<\/p>\n<\/figcaption><\/figure>\n But in the absence of a monsoon surge, less rain falling over the country could keep flooding at bay.<\/p>\n On Jan 2, the Meteorological Service Singapore (MSS) said in its fortnightly weather update that rainfall in the first half of the month is expected to be below average over most parts of the island. <\/p>\n An MSS spokesperson said a monsoon surge may be detected several days ahead using models that simulate the high pressure build-up over northern Asia and the stronger winds over the South China Sea.<\/p>\n To forecast a monsoon surge, MSS scientists rely on weather observations and computer models. The models take in current observations and solve complex equations that represent the physics of the atmosphere, MSS told ST. <\/p>\n During winter in the Northern Hemisphere, the chilly environment causes air over land to sink, producing high-pressure systems over Siberia and China, which periodically build up. <\/p>\n When this high pressure reaches a peak, it releases cold air in bursts. This sudden burst of cold air then surges over the warm South China Sea, picking up moisture as it travels. <\/p>\n At times near Singapore, the winds may interact with a separate whirlpool of air where winds are forced to move upwards, forming clouds. This is called a low-pressure vortex, which worsens the deluge over the country. <\/p>\n \u201cAs the surge gets closer, we rely increasingly on weather observations, such as from weather satellites, radar and weather stations, to monitor and track its development,\u201d added the MSS spokesperson. <\/p>\n Monsoon surges are easier to forecast because they are larger in scale compared with a short-lived thunderstorm over Ang Mo Kio, for example. <\/p>\n Surges can thus be simulated on weather models a few days ahead and, whenever possible, warnings are given at least a day in advance. <\/p>\n<\/picture><\/div>
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