Warmer weather, intense thunderstorms to start by end-Oct and last through Nov

SINGAPORE — After two weeks of wet weather in early October, the next two weeks of the month are expected to be drier and will usher in warmer temperatures and intense thunderstorms.

These conditions are characteristics of the inter-monsoon period, which will last through November, said the Meteorological Service Singapore (MSS) in a weather advisory on Tuesday (Oct 16).

Localised short-duration thundery showers are expected in the late morning and afternoon on five to seven days for the rest of October. On one or two days, however, widespread thundery showers accompanied with gusty winds are also forecast for the pre-dawn hours and early morning.

Lightning activity also tends to be higher than in other months of the year during inter-monsoon months, the MSS added.

The overall rainfall for this month is expected to be above normal over most parts of Singapore.

By the end of this month, the “low-level” wind conditions will weaken, and change from southeasterly or southwesterly to vary in direction, a sign that the Southwest Monsoon season is ending and the inter-monsoon period has started, the MSS said.

Warm weather will also be back in the second half of this month, with daily temperatures on most days to be between 25 deg C and 33 deg C. On a few days that have little or no rainfall, maximum daytime temperatures may reach about 35 deg C in the afternoon, the MSS said.

The dry and warm weather experienced at the beginning of this month, when temperatures hit a high of 35 deg C in some parts of the island, was due to stable atmospheric conditions in the region. The highest daily maximum temperature of 35.6 deg C was recorded on Oct 5 at the Marina Barrage.

In the second week of October, the rainy conditions were “due to the presence of persistent easterly winds bringing moisture from the Tropical Central Pacific Ocean to the southern Southeast Asia region”, the MSS said.

Rainfall across the island during the first fortnight of October 2018 was above normal, with Sentosa recording the highest rainfall of 224.0 mm — 170 per cent above average.

The daily maximum temperature on Oct 13 and Oct 14 fell to 30.1 deg C and 28.4 deg C respectively, and the lowest daily minimum temperature of 22.5 deg C was recorded around the Changi area on Oct 12.