New Delhi, Oct. 6 -- Thunderstorms, strong winds and heavy rain are expected across much of upper Thailand from Monday through Wednesday, increasing the risk of flash flooding, particularly in low-lying areas, the Thailand Meteorological Department said.

Very heavy to heavy rains are also forecast in some areas in the central, eastern and southern regions, including the capital, Bangkok, over the weekend.

Many areas in Bangkok were inundated last week after days of torrential rain, forcing thousands to evacuate and causing severe disruptions. The city's conditions have largely improved, although floodwaters remain in some lower-lying areas.

Bangkok authorities said they were taking measures to reduce the risk of further flooding, inclu...