Rain is forecast to blanket the northeastern, eastern and lower central regions with 14 provinces warned to brace for several days of heavy precipitation brought by a weakened tropical storm Vamco.
The Meteorological Department's latest warning came as Vamco lost steam and was downgraded to a low-pressure system with its centre over Surin and Buri Ram provinces on Tuesday afternoon. It was travelling westward at 37 kilometres per hour.
Vamco is bringing widespread rain on the lower parts of the northeastern, entire eastern and lower central regions, the weather bureau said. Heavy rain was expected in Ubon Ratchathani, Si Sa Ket, Surin, Buri Ram, Nakhon Ratchasima, Chaiyaphum, Lop Buri, Nakhon Nayok, Prachin Buri, Sa Kaeo, Chachoengsao, Chanthaburi and Trat provinces until Sept 18.
Storm Vamco moves deeper into Thailand from the northeastern region. (Meteorological Department photo)
The storm moved into Thailand through Ubon Ratchathani from Laos on Tuesday morning, bringing bad weather but welcome rain along with it.
Bad weather forced the pilots of Nok Air flight DD9310 to abort a landing in Ubon Ratchathani and return to Don Mueang on Tuesday morning for the safety of passengers and crew. The plane took off again from Bangkok for Ubon Ratchathani after a two-hour delay.
Heavy rain struck many parts of Chon Buri on Monday night, causing the interchange of the Chon Buri-Pattaya highway to flood before the Highways Department drained the water off the road on Tuesday morning.
The Provincial Administration Department ordered all provincial and district chiefs to be alert for problems caused by heavy rain and a warning of possible flashflooding was issued by the Disaster Prevention and Mitigation Department.
Bangkok was not directly hit by Vamco, but it still brought rainfall and wind to the capital on Monday.
The capital was preparing for possible floods due to the storm with 22 locations put on a close watch by the Bangkok Metropolitan Administration, as the weather bureau predicted rain in most areas until Wednesday.
City Hall has cleared the drainage system in all canals and installed pumps in several locations to clear water off streets in case of downpours.
Kangwan Deesuwan, director of the Drainage and Sewerage Department, said the prime concern was for the 22 risk spots as they could be easily flooded, causing traffic problems.
Areas prone to flooding include parts of the inner city such as the Royal Plaza, Yaowarat area and Phaya Thai Road.
But Vamco is a blessing for the Chao Phraya Dam in Sappaya district in Chai Nat province where the water level rose by 31 centimetres to 14.40 metres above mean sea level on Tuesday, allowing the operators to continue discharging enough water downstream to prevent salt water creeping up the Chao Phraya River and entering the city's water supply.
Dam director Ekkasit Sukdeethanaporn said runoff was entering the reservoir from provinces upstream which were now receiving rain and he expected the water storage level would continue to rise.