From late August, La Nina is expected to begin affecting Vietnam, with northern regions likely experiencing above-average rainfall in September. In particular, central Vietnam faces a heightened risk of intense rain and flooding in the year's final months.

Meteorologist Nguyen Van Huong, Head of the Weather Forecast Department at the National Center for Hydro-Meteorological Forecasting, recently provided analysis and forecasts regarding rainfall in August and the coming months.

August marks the primary rainy season for northern Vietnam, with the rain spell that started on July 28 possibly continuing until around August 3-4.

During this period, rainfall will mainly concentrate in the Northwest and Viet Bac regions, with localized areas experiencing heavy to very heavy rain. From August 5, heavy rain is expected to decrease; from August 6-7 onwards, the rain will continue to diminish and transition to sunshine.

From August 8-11, northern provinces are likely to experience a heatwave.

"We anticipate that if rain occurs in August, it will follow the heatwave, after August 11," said Huong.

According to expert Nguyen Van Huong, from late August and into September, La Nina will begin to take effect. Consequently, rainfall in northern Vietnam during September could exceed the multi-year average.

Significantly, from September, La Nina's impact coincides with the rainy and stormy season in central Vietnam. With this influence, storms and floods in central regions are likely to occur intensively from late September through October and November.

Huong added that in La Nina years, this phenomenon typically leads to rainfall above the multi-year average; the number of storms and tropical depressions also exceeds the average.

In northern Vietnam, the total rainfall since the start of the rainy season has generally been 30-80% higher than average, with some areas experiencing 80-100% more rainfall. Notably, in Bac Quang (Ha Giang) and Quang Ha (Quang Ninh), rainfall in June reached 1,105-1,271mm, double the same period.

According to the Department of Dike Management and Natural Disaster Prevention and Control, Ministry of Agriculture and Rural Development, preliminary statistics indicate that rains and floods in northern Vietnam over the past week have resulted in nine deaths, forced the emergency relocation of 63 households, and impacted nearly 600 houses with flooding.

Additionally, the rains and floods have submerged nearly 2,500 hectares of rice and crops, damaging 33.2 hectares of aquaculture. In terms of transportation, nearly 300 landslides and blockages have been reported.

The National Center for Hydro-Meteorological Forecasting reported that in August, total rainfall in northern Vietnam is expected to be around the multi-year average (5-10% higher); central Vietnam may see 15-30% less rainfall; in the Central Highlands and southern regions, rainfall is expected to be around the multi-year average (5-10% lower).

Moreover, during the forecast period, northern Vietnam, the Central Highlands, and the southern regions are expected to experience several days of rain, including some periods of moderate to heavy widespread rain. Thunderstorms in these areas may include tornadoes, lightning, hail, and strong winds.

During the forecast period, the number of storms/tropical depressions in the East Sea area is likely to be below the multi-year average (2-3 storms).

Heatwaves in August are expected to continue in northern and central Vietnam, but the intensity will not be too severe. The average temperature across the country is expected to be 0.5-1 degrees higher than the multi-year average.

According to meteorological experts, this year, the appearance of La Nina is likely to complicate and make the storm season unpredictable. Notably, storms that significantly affect Vietnam typically occur at the end of the year.

Bao Anh