The Ministry of Water Resources and Meteorology issued an emergency warning on Tuesday night, advising citizens to take precautions against incoming tropical storm Haima.
The storm originated over the South China Sea and is expected to hit Cambodia by tomorrow, with effects concentrated in the northern and northeastern highlands as well as along the coast.
The Macau Meteorological and Geophysical Bureau issued a typhoon signal number 3 yesterday, a designation reserved for wind speeds between 41 and 62 kilometres per hour.
On-duty forecaster Ketty Lam said the Bureau might raise a higher signal in the unlikely scenario that the storm deviated from its present path.
Lim Kean Hor, Minister of Water Resources and Meteorology, said in the statement that Preah Vihear, Oddar Meanchey, Stung Treng, Ratanakkiri and Mondulkiri provinces could experience heavy rain and flash flooding.
He said Koh Kong, Preah Sihanouk, Kep and Kampot could also experience intense rain, high winds and waves as high as two metres.