KUALA LUMPUR, Feb. 18 -- The Malaysian Meteorological Department (MetMalaysia) has issued a thunderstorm warning for several areas in Pahang, Johor and Sarawak, while forecasting a monsoon surge that could bring prolonged heavy rain to Sabah and Sarawak later this week.

In a post on its official Facebook page this morning, MetMalaysia said thunderstorms, heavy rain and strong winds are expected in Pahang (Jerantut, Kuantan, Pekan and Rompin), Johor (Mersing), and parts of Sarawak including Kuching, Samarahan, Bintulu and Subis in Miri until 10am today.

The department said the warning was issued at 6am and explained that thunderstorm alerts are released when there are signs of rainfall exceeding 20mm per hour that is imminent or expected...