The Malaysian Meteorological Department (MetMalaysia) has forecast heavy rain in three states this afternoon.
In a statement, MetMalaysia said the affected areas are Perlis, Kedah and Penang.
“Thunderstorms, heavy rain and strong winds are expected in Perlis, Kedah (Langkawi) and Penang (Southwest) until 3pm today,” it said.
The warning is issued when conditions indicate that thunderstorms with rainfall intensity exceeding 20mm per hour are occurring or expected to occur for more than an hour.
MetMalaysia said thunderstorm warnings are short-term alerts, with each warning valid for no more than six hours.

