A weather warning has been issued for 19 provinces in the northern and northeastern regions, some of them already dealing with floods, as tropical storm Dianmu moves toward the country.
In the North, 11 provinces are possible targets of the storm: Chiang Mai, Chaing Rai, Lampang, Lamphun, Mae Hong Son, Nan, Phayao, Phitsanulok, Phrae, Tak and Uttaradit. The northeastern provinces are Bueng Kan, Nong Bua Lam Phu, Nong Khai, Loei, Phetchabun, Nakhon Phanom, Sakhon Nakhon and Udon Thani.
They could encounter "heavy to very heavy rain" until Saturday, the Meteorological Department said in its latest warning. "People should beware of the severe conditions," it added.
The Disaster Mitigation and Prevention Department said it expected harsh weather conditions to persist until Sunday and alerted its officials in the two regions to stand ready for possible floods, strong winds and landslides in some areas.
Floodwater was draining off in Mae Hong Son and Phayao but low-lying areas of Nan and Phrae were still inundated on Friday.
At least Dianmu, which moved into Laos and Vietnam on Friday, is expected to be downgraded to a depression when it reaches Thailand, the weather agency said.
The tropical storm dumped more than 300 millimetres of rain on parts of Hainan Island in southern China earlier in the week. Rainfall has already totalled more than 150mm in parts of northern Laos and Vietnam, including areas around Hanoi, according to Accuweather.
Provincial governors in Nan, Lamphang and Phayao have radioed all district chiefs to be prepared for the storm and move people living in at-risk areas to high ground for safety.
Thanawut Panjaporn-udomlarp, the director of the Northeastern Meteorological Centre based in Khon Kaen, also warned people along the Mekong River to keep a close watch on the water level.
"Heavy rains are expected this weekend and the water level of the Mekong River could rise," he said.
Prime Minister Prayut Chan-o-cha on Friday also warned people in the provinces identified by the weather bureau to be cautious about possible floods and runoff, government spokesman Maj Gen Sansern Kaewkamnerd said.
The reservoir at the Kwai Noi Bumrung Dan dam is 40% full and is about to fill up some more. (Photo by Chinnawat Singha)
While officials stand alert for the coming storm, operators of the Kwai Noi Bumrung Dan dam in Phitsanulok is looking forward to rain to replenish its water stocks.
Dam director Chalermsak Taksadiwong said he hoped that rain in the coming days would help offset the problems caused by dry conditions last week.
Water in the reservoir on Friday stood at 371 million cubic metres, which is only 40% of its capacity, he said.
