SINGAPORE - Thundery showers fell across most of Singapore on Friday (April 20), with flash floods occurring in Ang Mo Kio and on the Pan-Island Expressway.

The Land Transport Authority (LTA) said on its traffic news Twitter channel at 5.18pm that there was a flash flood in Ang Mo Kio Avenue 1, towards Ang Mo Kio Avenue 2, after Ang Mo Kio Avenue 3.

LTA said about 40 minutes later that there was another flash flood on the PIE, towards Tuas, at the Kranji Expressway or Bukit Timah Expressway exit.

The flood affected one of the two lanes there and subsided almost an hour later at 7pm, PUB said.

National water agency PUB also issued flood alerts for a few areas in the central region.

The National Environment Agency had issued an alert for heavy rain at 4.10pm, saying the downpours are expected over northern, western and central areas of Singapore for an hour.

According to NEA's two-hour forecast, thundery showers, some with gusty winds, are expected between 4pm and 6pm over most of the island except parts in the east.

The rain prompted PUB to issue flood alerts for Tanjong Pagar Road and Craig Road, Gul Circle, Veerasamy Road and Bishan Road.

PUB's real-time closed-circuit television cameras showed water levels in its measuring drains rising above 90 per cent in several areas.

The Meteorological Service Singapore had previously forecast more thundery showers in the second half of April, which are expected mainly in the afternoon on seven to nine days.