KUALA LUMPUR, Aug 18 — The Malaysian Meteorological Department (MetMalaysia) has issued a warning for thunderstorms, heavy rain and strong winds across several areas in Peninsular Malaysia until 9pm today.In a statement, it said the affected areas include the whole of Perlis and several districts in Kedah, namely Langkawi, Kubang Pasu, Kota Setar, Pokok Sena, Padang Terap, Yan and Pendang.A similar warning has also been issued for several areas …