The Meteorological Department on Saturday warned residents of Bangkok and the Eastern and lower Central provinces to brace themselves for heavy rains and possible flash floods on Sunday and Monday.
The department said in a fourth warning issued at 11am that rains would be unleashed by Tropical Storm Kirogi, which has downgraded to a tropical depression over the middle of the South China Sea.
As of 10am Saturday, the department said, the storm was located at latitude 10.9 degree North and longitude 114.6 degree East. With sustained winds of 65 kilometres per hour, the storm was moving west-northwest at speed of 27 km/hr.
The storm is expected to make landfall over middle Vietnam and Cambodia sometime between November 19 and 21.
More rain with isolated heavy downpours is likely in the East, the lower Central including Bangkok and its vicinity, and the South, the department added.
Affected areas are as follows:
From November 19-20: Kanchanaburi, Ratchaburi, Prachin Buri, Sa Kaew, Chon Buri, Rayong, Chanthaburi, Trat, Prachuap Khiri Khan, Chumphon and Surat Thani including Bangkok and its vicinity.
November 20-21: Prachuap Khiri Khan, Chumphon, Surat Thani, Ranong, Phang Nga and Phuket.
The department added that a rather strong high-pressure system over southern China was tending towards upper Vietnam and Laos on Saturday. Overnight on Saturday, the system is forecast to cover the Northeast of Thailand, and later the North and the upper Central regions.
As a result, thundershower outbreaks will be likely at the beginning of the period, followed by cool spells, with the temperature decreasing by 2-4 degrees Celsius.