The Meteorological Department has issued a warning for people in 28 provinces in the North, Northeast and East to brace for heavy rain and stay tuned for weather updates.
As of 4am on Tuesday tropical storm "Rai" over the coast of Vietnam became a depression centered about 150 kilometres east of Da-Nang, Vietnam, with maximum sustained winds around 65 kilometres per hour.
The tropical depression was moving west-northwest at 20kph. It was expected to make landfall at Da-Nang, Vietnam, on Tuesday and move toward the middle Northeast of Thailand by tonight.
Isolated heavy to very heavy rain is likely to prevail over Sakon Nakhon, Nakhon Phanom, Mukdahan, Amnat Charoen, Ubon Ratchathani, Surin, Buri Ram, Si Sa Ket, Roi Et, Kalasin, Khon Kaen, Chaiyaphum and Nakhon Ratchasima in the Northeast; Prachin Buri, Chon Buri, Rayong, Chanthaburi and Trat in the East; and Chiang Mai, Chiang Rai, Phayao, Nan, Phrae, Lamphun, Lampang, Uttaradit, Phitsanulok and Phetchabun in the North.
People should brace for severe weather conditions and all travelers should stay tuned for weather updates.
The Disaster Prevention and Mitigation Department has placed its offices in the 28 provinces on standby with rapid mobile units ready to be deployed to troubled spots.
In Chaiyaphum, about three hours of continous rain fell late on Monday night, flooding the provincial town's business area.
The road passing the provincial hospital and Chao Pho Phaya Lae statue was 20-30 centimetres under water and impassable to small vehicles.
The Chaiyaphum Municipality had used water pumps to drain water out into public waterways.
Steady rain was reported in much of Buri Ram throughout Monday afternoon.