In its 13th warning related to storm Doksuri issued at 4am on Saturday, the department said the tropical storm, which has been downgraded from a typhoon, is centred over Vientiane, Laos 120km east of Nan Province at latitude 18.3 degrees North, longitude 102.1 degrees East.
With maximum sustained winds of about 65 km/hr, the storm is moving west at speed of 30km/hr and is forecast to downgrade again to a tropical depression.
Widespread rains are expected throughout much of the North and the Northeast. Torrential downpours are predicted with gusty winds.
With the added influence of a strong southwest monsoon over the Andaman Sea, the South and the Gulf of Thailand, meteorologists predict abundant rain with torrential downpour in the Central, the East and the South.
The department warned that the following provinces would be affected by heavy rains and strong winds:
North: Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Phrae, Nan, Lamphun, Lampang, Uttaradit, Phitsanulok, Sukhothai, Kamphaeng Phet, Tak and Phetchabun.
Northeast: Loei, Nong Bua Lam Phu, Nong Khai, Bueng Kan, Udon Thani, Sakon Nakhon, Nakhon Phanom, Khon Kaen, Chaiyaphum, Kalasin, and Nakhon Ratchasima.
Central: Nakhon Sawan, Uthai Thani, Chai Nat, Lop Buri, Saraburi, Sing Buri, Kanchanaburi, Ang Thong, Ratchaburi, and Phra Nakhon Si Ayutthaya including Bangkok and its vicinity.
East: Nakhon Nayok, Prachin Buri, Sa Kaeo, Chon Buri, Rayong, Chanthaburi and Trat.
South: Surat Thani, Nakhon Si Thammarat, Phattalung, Songkhla, Ranong, Phangnga, Phuket, Krabi, Trang and Satun.
The warning added that small boats should not leave the shore until Monday as two to three-metre-high waves are expected in the seas.