After suffering one year of severe drought from El Nino, Thailand is now bracing itself for La Nina, another weather phenomenon that is expected to bring excessive rainfall.
The agricultural and industrial sectors that were threatened by a lack of water face the prospect of being inundated with rain this year, according to government and industry sources.
Meteorological Department director-general Wanchai Sakudomchai said the hot season has ended and the country is now in the rainy season, which is expected to last longer than expected.
"This is seasonal heavy rain that may last until October. However, what we need to monitor are the seasonal storms that hit Thailand every year," he said.
Mr Wanchai said two tropical storms generally hit Thailand each year. However, the longer-than-expected rainy season could escalate normal tropical storms to be powerful depressions or devastating typhoons that could destroy farmland and communities while inundating industrial estates, especially those in low-lying areas.
"We need to check from time to time how many storms will hit Thailand during the stormy season that is likely to start in July and last through October," he said.
After the end of the normal rainy season in October, Thailand is expected to be hit by La Nina. The phenomenon will cause higher moisture evaporation in the Pacific Ocean that will create abnormal rain and storms. It could cause floods in several Southeast Asian countries, with the North and Northeast of Thailand at risk.
"That would be the same timing as the rainy season in the South, meaning we could see excessive rain and even flash floods, especially in the South," said Mr Wanchai.
He said excessive rain would be a positive factor for the farming sector as it would help refill major reservoirs across the country to ensure there would be sufficient water supply next year.
However, this might not be good news for the industrial sector, which completely depends on flood protection systems.
Torrential rain has started hitting Bangkok and its outskirts this week, causing knee-high floods in the business district and Bangpoo Industrial Estate in Samut Prakan province, about 30 kilometres from the centre of the capital.
The flooding disrupted operations at 15 factories in the industrial estate and also raised concerns among others factory owners in other regions.
Chen Namchaisiri, chairman of the Federation of Thai Industries, said the government should be better prepared for variable weather patterns than in the past because La Nina is a predictable weather phenomenon.
He blamed authorities' negligence for the recent flood at Bangpoo Industrial Estate, which would have been unaffected if the government had prepared measures to deal with expected heavy rain.
"I don't understand what they were doing then," he said.
Mr Chen urged authorities to prepare properly for La Nina. "The weather pattern is a predictable one and everybody knows that it normally comes after the end of El Nino. Why don't they start to prepare for it?" he asked.
Veerapong Chaiperm, governor of the Industrial Estate Authority of Thailand, said it had alerted all involved agencies to prepare for rain and flooding in order to protect industrial estates from being inundated, especially those estates in Ayutthaya and other low-lying areas that were devastated by severe flooding in 2011.
"Each estate has its own plan to deal with floods and the authorities are on alert to apply flood protection measures if needed," he said. "As both the authorities and the private sector have had strong experience of floods in recent years, we are confident that we can manage to get through it safely."
The great flood of 2011 caused damage estimated at 1.49 trillion baht.