Seven to nine more storms possible as northern floods ease

Flood conditions in Nan and Sukhothai have begun to improve, but another 7-9 storms could form before the end of the current storm season, climate and disaster specialist Assoc Prof Dr Seree Supratid has warned.

Seree, director of the Climate Change and Disaster Centre at Rangsit University, said in a Facebook post that rainfall was expected to decline gradually through the end of August. Weather conditions would still require close monitoring on August 25-26 and again around August 29.

A storm system near China’s Hainan Island could bring increased rainfall to several areas, although Seree expected it to be less severe than the conditions recorded on August 19. 

Western areas, the upper North, upper Northeast and East face the greatest risk of heavy rain.

Another 7-9 storms could develop

Seree said 18 storms had formed so far this season, including five typhoons, with another 7-9 storms still possible during the remainder of the season.

Despite the number of storms, relatively few have moved into Thailand this year. Seree linked this partly to strong El Niño conditions, which historical data indicate can reduce the likelihood of storms reaching the country.

His analysis identified four climatic factors that can alter storm tracks during a strong El Niño:

1. Storm formation shifts farther east, changing the routes taken by developing systems.
2. Monsoon winds and easterly trade winds weaken, affecting the direction and strength of storms.
3. The monsoon trough weakens and moves northwards, shifting rainfall patterns and storm paths.
4. High-pressure systems change position, influencing the movement of storms and rain systems.

Seree cautioned that storms and weather variability could still increase rainfall in some locations despite the improving flood situation.

Conditions should therefore be monitored particularly closely on August 25-26 and towards the end of the month.