More heavy rain is forecast for the Lower North, Northeast and Central regions through to Tuesday as Tropical Storm Conson approaches and makes landfall on mainland Southeast Asia.
The Meteorological Department said yesterday that the powerful storm was over the upper South China Sea and moving west at about 20km per hour.
The storm is expected to intensify over the weekend and make landfall in central and upper Vietnam on Monday before weakening. This will bring prolonged and torrential rain over Thailand.
Small vessels are warned not to put to sea in both the Andaman Sea and Gulf of Thailand until at least Tuesday or until the all-clear is given, the department said.
The latest weather warning extended the period of the storm's impact from Sunday to at least Tuesday.
Rain has covered most parts of the country since last Tuesday, with flooding in 20 provinces. No fatalities have been reported.
In Nakhon Ratchasima, Lam Phra Phloeng dam held 123 million cubic metres of water yesterday, or about 79% of its storage capacity of 155 million cu/m.
About 1.2 million cu/m of water was released into irrigation canals and another 1.5 million into larger canals.
As a result, water discharge from the dam, along with heavy rain, burst canal banks and flooded Ban Bupho in Pak Thong Chai district as well as more than 50 rai of rice fields. The village is in an area often hit by rain-triggered flooding during the rainy season.
In Phitsanulok's Wang Thong district, municipality officials, volunteers and local residents raced to fill sandbags to prevent water surging up through drainage pipes and flooding the municipality's main market.
A close watch is being kept on the rising water level in the Wang Thong River, measured at 8.5 metres yesterday. The river also burst its banks and flooded a vast area containing rice fields and canal networks which serve as water retention areas.
In Phetchabun, a huge water surge in the Pa Sak River flowed from Lom Kao district bursting banks in Lom Sak district on Thursday night, flooding several riverside communities in the Tarn Diew municipality.
A road in Ban Sri Sa-ard was under 80 centimetres of water while a flooded intersection on the Lom Sak-Ban Tiew road was impassable to small vehicles.
The Lom Sak museum located on the banks of the Pa Sak River at Wat Thung was also flooded while officials raced to build a levee comprising more than 10,000 sandbags to protect other communities from the overflowing river.
In Prachin Buri, water runoff from national parks caused flooding in a riverside community in Kabin Buri district.
The water from Khao Yai National Park, Thap Lan National Park and the Thap Lan reservoir caused the Prachin Buri River to overflow into the Talad Kao community in tambon Kabin.
About 50 homes were inundated forcing residents to move belongings to the second floor of their homes.