This morning (November 26), the General Department of Meteorology and Hydrology held an online meeting to assess the path and intensity of Typhoon Koto.

According to the National Center for Hydro-Meteorological Forecasting, as of the night of November 25, Koto entered the East Sea and officially became the 15th storm of the year. It reached category 8 with gusts up to category 10.

However, meteorologists emphasized that there remains significant variation in how international models and forecasting agencies predict Koto’s next moves.

Two possible scenarios for Typhoon Koto

From now until November 28, Typhoon Koto is expected to move west-northwest, then mainly westward at about 20 km/h. Around the time it nears 113°E longitude, a weakening subtropical ridge and the emergence of a low-pressure trough in the mid-troposphere (around 5,000 meters altitude) may influence its direction and intensity. This introduces multiple potential scenarios for its future path and impact on Vietnam’s waters and mainland.

The most likely scenario, with about an 80% probability, is that the typhoon will shift northward upon entering the northwest sea zone of the Truong Sa (Spratly) Archipelago, remaining about 500 km east of the Gia Lai–Khanh Hoa coastline.

In this case, as the typhoon nears 113°E, it could curve northward and weaken into a low-pressure system, which might drift toward central Vietnam but would dissipate before reaching land.

Under this forecast, strong winds of category 6–7 are expected in the eastern sea areas of the central East Sea. Near the storm’s center, winds may reach category 8–9 with gusts up to category 11, accompanied by waves 4–6 meters high and very rough seas.

From November 27, the central East Sea, including the northern Spratly waters, could face winds of category 10–11, gusts up to 14, and waves as high as 6–8 meters.

In this scenario, mainland areas are unlikely to experience direct storm-force winds.

Nonetheless, due to the storm’s influence, a widespread rain event may occur between early December 2025 in areas from Da Nang to Lam Dong, especially in coastal zones.

“Based on current analysis, this rain event is unlikely to be as extreme as the one from November 16–21,” experts noted.

The less likely, but more severe scenario (with a 20% probability), is that the typhoon maintains its westward course and heads directly for the Gia Lai–Khanh Hoa area.

In this case, Koto could strengthen to category 11 with gusts up to 13 as it moves through the northern Spratly region. Then, it would continue westward toward central Vietnam, particularly Gia Lai and Khanh Hoa, possibly weakening to category 8 or into a tropical depression upon landfall.

If this scenario occurs, the coastal zones from Da Nang to Lam Dong could experience category 8 winds with gusts up to 10, sea waves of 3–5 meters, and rough seas from November 29 onward.

Rainfall in these coastal areas could range from 150–250mm between November 29 and December 1.

Monitoring the impact of post-storm cold air

At the meeting, Deputy Director Hoang Duc Cuong urged local meteorological stations to increase forecast updates and standardize reporting in line with current projections. He emphasized the need for timely communication to provinces already hit hard by previous flooding, such as Quang Ngai, Gia Lai, Dak Lak, Lam Dong, and Khanh Hoa.

Cuong also stressed the importance of continuing to monitor the effects of cold air following the typhoon, ensuring clarity in public weather bulletins.

Director Nguyen Thuong Hien highlighted the need to ensure accuracy and clarity in all forecast data, especially regarding impact levels, affected regions, and quantifying expected wind and wave conditions at sea so the public can respond appropriately. Rainfall forecasting remains a particular focus of concern.

Bao Anh