More hot days with temperatures above 34 deg C to come after third warmest February in years

Goh Yan Han Straits Times 6 Mar 19;

SINGAPORE - Singaporeans can expect warmer days ahead, with the mercury going beyond 34 deg C more often.

The daily maximum temperature is expected to exceed 34.1 deg C on more days in the future, said the Meteorological Service Singapore (MSS) on Tuesday (March 5).

Singapore's annual temperature has been steadily rising over the last 25 years and MSS' climate projections indicate that with global warming, there is a greater likelihood of more heat extremes.

The authority was responding to queries from The Straits Times after it was reported last week that February 2019 was the third warmest February since 1929.

Experts have said that Singapore will face more extreme weather conditions due to climate change, including rising temperatures, prolonged dry spells and more intense rainfall.

For last month, the weather was drier and warmer than usual "due to stronger solar heating of land areas and less cloudiness", said the MSS. The mean monthly temperature for February 2019 was 28.2 deg C.

February is usually the driest month of the year, while the warmest months are typically April, May and June.

MSS said that February's warm conditions could be attributed to a high pressure system over the Pacific Ocean that extended towards the South China Sea and the surrounding South-east Asia region.

A high pressure system is associated with sinking air, giving rise to fewer clouds and more stable atmospheric conditions, the authority explained.

Another factor that contributed to the dry and warm weather was the Madden-Julian oscillation that was in its dry phase over the South-east Asia region.

"The Madden-Julian oscillation is a large-scale atmospheric phenomenon that is characterised by an eastward propagation of both enhanced (wet phase) and suppressed (dry phase) rainfall and cloudiness over the tropical regions from the Indian Ocean to the western Pacific Ocean, with each cycle lasting about 30 to 60 days," said the MSS.

The other warmest Februarys were in 1998 and 2010 (28.9 deg C for both years), as well as in 2005 (28.5 deg C).

Both 1998 and 2010 experienced strong El Nino phenomena in February.

In February 2005, the warm conditions were due to the influence of a high pressure system in northern Asia coupled with an active dry phase of the Madden-Julian oscillation over the South-east Asia region, said MSS. These reasons are similar to those behind the warm conditions of February 2019.

MSS said that for any given month, temperatures experienced are due to a combination of year-to-year natural climate variability and the underlying long-term warming trend associated with global warming that has been affecting Singapore and the wider region.

Natural climate phenomena such as El Nino and the Madden-Julian oscillation can amplify underlying global warming effects, making the weather much warmer than normal, it added.

Global warming can also cause changes to regional weather patterns and redistribute rainfall, leading to changes in the frequency and severity of dry and wet periods, which could potentially affect Singapore's water resources, said MSS.

As the atmosphere warms, it can also hold more water vapour. In terms of the impact on human health, the combined effect of high temperature and high humidity can increase the risk of heat-related illnesses like heat stroke for the most vulnerable.

The increased moisture in the air could also lead to more intense rain.