Flash floods and forest water runoff are expected to hit 40 provinces during downpours tomorrow, the Thai Meteorological Department (TDM) warned.
Mae Hong Son in the North, Loei in the Northeast, Nakhon Sawan in the Central region, and Nakhon Nayok in the East are expected to be hit hardest tomorrow, the department said.
Scores of provinces are already battling floods brought by a monsoon from the northern region.
The department predicted that in the South, heavy rain caused by the southwest monsoon will affect the upper part of the Andaman Sea.
The hardest-hit area so far is Phrae province. At 9am yesterday downpours brought by Tropical Storm Higos caused floods in tambon Toon Kwow in Muang district.
Because of its high terrain, the heavy flooding resulted in runoff and a mudslide that obstructed roads, including Highway 1022 (Pa Daeng-Natong) in tambon Cho Hae in Muang.
Many local roads are reportedly cut off by mud and rainwater. Five villages in tambon Pa Dang and tambon Cho Hae in Muang were cut off as mud blocked access to main roads.
Meanwhile, water in an irrigation canal in tambon Hua Fai in Muang reportedly overflowed onto roads in Moo 7 and 8. Floods have damaged 10 houses in tambon Thung Kwao.
In Nan province, a man reportedly died after drowning in the Nan River yesterday.
Klai Sonrsamrit, 62, a villager from Santisuk district, was reportedly swept away by the river's current as he went fishing during a flash flood. Rescue officials retrieved his body two hours later.
Heavy rain caused water in the Nan River and its tributaries to overflow into communities in the districts of Muang, Phu Phiang, Winag Sa and Pua. A total of 213 families were forced to evacuate.
In Lampang province in the northern region, forest runoff from the Chae Son National Park flooded four villages with more than 100 households.
Tropical Storm Higos is said to be affecting farmlands in Roi Et province, where more than 2,000 rai of land was inundated.