The WMO said Indonesia, the Philippines, Sri Lanka, Thailand and Vietnam are among the countries most severely affected by the "combined monsoon and tropical storm activity".
Speaking in Geneva (Switzerland) on December 2, WMO spokesperson Clare Nullis emphasized that Asia is extremely vulnerable to floods and according to annual climate reports (State Of The Climate), floods are always at the top of the region's list of climate hazards.
Nullis added that typhoons forming near the equator - such as Senyar, which caused flash floods and landslides in North Sumatra (Indonesia), Malaysia and southern Thailand last week - are rare. It is this abnormality that makes the level of destruction more serious, because the local community has almost no experience in coping.
Data from the Indonesian National Disaster Management Board (BNPB) released on December 2 shows the catastrophic level of the recent natural disaster: 712 dead, 507 missing, and about 2,600 injured. A total of 1.1 million people were affected and more than 570,000 people were evacuated in 50 counties on Sumatra Island.
According to the WMO, Vietnam has been struggling with heavy rains for many consecutive weeks and is currently facing the risk of receiving more extreme rain.
Prolonged rains have caused many relics and tourist attractions to be deeply flooded, causing economic losses of up to tens of millions of USD, especially in agriculture. More than 100 people have died in the flood from November 16-20 alone.
Under the combined impact of storm No. 15 Koto, although it has weakened into a tropical depression and cold air, the coastal areas of the South Central Coast and Central Highlands of Vietnam are forecast to have heavy to very heavy rain on December 3-4.
In the period of November 16-20 alone, easterly wind disturbances combined with increased cold air caused widespread heavy rain, with common rainfall of 400-700mm, many places exceeding 1,000mm. In eastern Dak Lak alone, 700-900mm was recorded, with some points exceeding 1,200mm, according to the Vietnam National Center for Hydro-Meteorological Forecasting. Many rivers such as Ky Lo, Ba River (Dak Lak) and Dinh River (Khanh Hoa) exceeded the historical flood level.
At the end of October, a meteorological station in Hue recorded 1,739.6mm of rain in 24 hours - a level never seen in Vietnam. The WMO said the value is being assessed by the extremes Evaluation Committee and if confirmed, it will be a record for the Northern Hemisphere and Asia, near the world's highest point (1,825mm).
Not only Vietnam and Indonesia, but also Sri Lanka are in a humanitarian crisis after Typhoon Ditwah made landfall last week, affecting 1.4 million people, including 275,000 children.
Explaining the sharp increase in extreme weather phenomena, Ms. Nullis affirmed: Increased temperatures increase the risk of extreme rain, because warm air contains more moisture. That is the law of physics.
She warned that the world will continue to witness unusually heavy rains in the future - a particularly worrying risk for countries like Vietnam, where the impact of climate change is increasingly present.
