Typhoon No. 15 (Koto) has started to slow down but may intensify by two levels in the next 24 hours. Its presence in the East Sea is projected to last nearly six days. Central Vietnam, especially areas recently affected by flooding, should remain on high alert for heavy rain and landslides.

According to the National Center for Hydro-Meteorological Forecasting, as of 1:00 p.m. on November 26, the storm's center was located about 280 km east-northeast of Song Tu Tay Island. Maximum sustained winds near the center reached level 9 (75–88 km/h), with gusts up to level 11. The storm is currently moving west-northwest at about 20 km/h.

Within the next 24 hours, the storm is expected to maintain its west-northwest trajectory but slow to around 10 km/h and intensify further. By 1:00 p.m. on November 27, the center is forecast to be in the central East Sea, about 150 km north of Song Tu Tay Island, with wind speeds reaching level 11 and gusts at level 14  -  expected to be the storm’s peak intensity.

Over the next 24 hours, the storm may shift west-southwest with a very slow pace of about 5 km/h. By 1:00 p.m. on November 28, its center would remain over the central East Sea, about 200 km northwest of Song Tu Tay, with intensity maintained at level 11 and gusts at level 14.

Another 24 hours later, the storm is likely to change direction again, heading northwest at a continued slow pace of 5 km/h. By 1:00 p.m. on November 29, the center will be over the western part of the central East Sea, with wind speeds of level 10–11 and gusts at level 14.

From 72 to 120 hours after, the storm is expected to drift slowly north-northwest at 3–5 km/h and gradually weaken.

Meteorologists suggest two possible scenarios for Typhoon No. 15 (Koto). The most likely  -  with an 80% probability  -  is that the storm will veer northward after entering the northwestern waters of the Spratly Islands, about 500 km east of the Gia Lai–Khanh Hoa coast.

Specifically, upon reaching longitude 113°E, it may turn north and weaken into a low-pressure area. This system could then drift toward the mainland in central Vietnam and dissipate offshore. Under this scenario, the mainland would be unlikely to experience strong winds.

However, due to the storm’s influence, the region from Da Nang to Lam Dong may still face widespread rainfall in early December, with coastal areas most at risk.

“Based on current data, this rainfall event is not expected to be as extreme as the one from November 16–21,” experts noted.

A less likely but more serious scenario  -  with a 20% probability  -  is that the storm stays on course and heads straight toward Gia Lai–Khanh Hoa.

In that case, the storm would maintain peak intensity near the northern Spratly Islands at level 11 with gusts at level 13, before continuing west toward the central coast. It would likely weaken to a level 8 storm or a tropical depression.

If this happens, strong winds of level 8 and gusts at level 10 could hit coastal provinces from Da Nang to Lam Dong starting November 29, with waves reaching 3–5 meters and rough seas expected.

Additionally, this coastal stretch may receive heavy rainfall of 150–250 mm between November 29 and December 1.

Deputy Minister of Agriculture and Environment Nguyen Hoang Hiep emphasized two key characteristics of this storm that remain consistent across all forecast scenarios.

First, Typhoon Koto will linger over the sea for an unusually long time  -  nearly six days from November 27 through December 1.

During this period, the storm’s center and surrounding impact zone will remain over the Spratly Islands and parts of the Paracel Islands.

“Given this forecast, we must strictly ban all maritime activity in the affected area during this time. No fishing boats or vessels should venture out,” Hiep stressed.

Second, Hiep warned that Koto will bring rainfall to areas from Gia Lai to Khanh Hoa  -  regions already severely impacted by recent floods. Even though expected rainfall may be only 50–70 mm, the risk of landslides remains high due to already saturated soil.

For now, due to the storm’s impact, the central East Sea (including the northern Spratly Islands) is experiencing strong winds at level 7–8. Areas near the storm center are seeing wind speeds of level 9–11 with gusts at level 14, waves 4–6 meters high, and up to 9 meters near the storm’s core  -  causing violent sea conditions.

All vessels in these zones are at risk of thunderstorms, strong winds and large waves.

Bao Anh