The department said residents in Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala, Narathiwat, Phangnga, Phuket, Krabi, Trang and Satun should beware possible flash floods. 
It said the rain would be triggered by a strong northeast monsoon over the Gulf of Thailand and the South, with waves up to 2-3 metres high likely in the Gulf and the Andaman Sea. 
Ships should proceed with caution, small boats in the Gulf should stay ashore and residents should also beware the powerful waves coming on to land, said the department. 
The warning was issued at 5am on Monday.

Southern provinces warned of heavy rain

The Meteorological Department has warned people in 11 southern provinces to brace themselves for more heavy rain on Monday and Tuesday.