The tropical depression, a remnant of Storm Koto (Storm No. 15), is expected to weaken into a low-pressure area within the next 24 hours. Forecasts indicate that several central provinces in Vietnam will begin to see widespread moderate to heavy rain.

According to the National Center for Hydro-Meteorological Forecasting, the tropical depression - formerly Storm Koto - has remained nearly stationary over the East Sea during the past 24 hours. It is projected to weaken into a low-pressure area within the next day.

As of 7:00 AM on December 2, the depression’s center was located over the northwestern part of the central East Sea. Maximum sustained winds near the center reached Level 6 (39–49 km/h), with gusts up to Level 8.

The depression is slowly drifting south-southwest at approximately 5 km/h.

Over the next 24 hours, the system is expected to continue on its current track at a speed of 5–10 km/h while gradually weakening into a low-pressure area. By 7:00 AM on December 3, its center is forecast to be over the waters between Dak Lak and Khanh Hoa provinces, with wind speeds dropping below Level 6.

Cold air front approaching northern Vietnam

The weather agency also reported that a cold front will begin affecting the northeastern region, north-central region, and parts of the northwestern region from the early hours of December 3. It will later extend to other areas in the northwest and parts of the central coast.

As a result of the cold air, the North and north-central regions will experience cold weather from the night of December 3. Some mountainous areas in the North may even see severe cold. Temperatures during this period are expected to range from 15–18°C (59–64°F) in lowland areas and 13–15°C (55–59°F) in mountainous regions, with some high-altitude locations dropping below 11°C (51.8°F).

In Hanoi, cold weather is expected to arrive on the night of December 3, with temperatures falling to 15–18°C (59–64°F).

Central Vietnam braces for heavy rain

 
Of particular concern is the interaction of the incoming cold front with the residual circulation of the weakening tropical depression, coupled with disturbances in the upper-level easterly winds. This combination is expected to trigger moderate to heavy rainfall across central provinces from December 2 to 5.

Last night and early this morning, scattered showers and thunderstorms occurred in areas from Quang Tri to Da Nang, and in eastern regions from Quang Ngai to Dak Lak.

From the night of December 2 to the end of December 3, Da Nang, Hue, eastern Quang Ngai, Dak Lak, and Khanh Hoa may receive 40–100 mm (1.6–3.9 in) of rain, with localized totals exceeding 150 mm (5.9 in).

By the night of December 3, areas from Quang Tri to Da Nang and eastern Quang Ngai may experience another round of 20–40 mm (0.8–1.6 in) of rain, with some locations exceeding 70 mm (2.8 in). Heavy rainfall rates above 100 mm (3.9 in) over three hours are possible.

Rainfall is expected to persist into December 4, with affected regions seeing another 30–70 mm (1.2–2.8 in), and isolated areas exceeding 120 mm (4.7 in).

Cumulative rainfall from December 2 to the end of December 4 may reach 100–200 mm (3.9–7.9 in) in Hue, Da Nang, and eastern Quang Ngai, with some areas exceeding 300 mm (11.8 in). Areas such as Quang Tri and eastern parts of Gia Lai, Dak Lak, and Khanh Hoa may see 40–100 mm (1.6–3.9 in), with isolated totals over 150 mm (5.9 in).

The meteorological agency warns of possible flooding in low-lying and urban areas, flash floods in small rivers and streams, and landslides on steep slopes.

Dangerous sea conditions expected

Due to the approaching cold front, northeast winds in the Gulf of Tonkin are expected to strengthen to Level 6 (39–49 km/h) by the morning of December 3, with gusts reaching Level 7–8. The sea will be rough, with wave heights from 2–4 meters (6.6–13.1 feet).

In the northern East Sea, northeast winds will strengthen to Level 6–7 with gusts up to Level 9, producing waves from 3–5 meters (9.8–16.4 feet). From the afternoon of December 3, seas off the coast from southern Quang Tri to Hue and northern parts of the central East Sea will also see rising winds and waves of 3–5 meters.

Bao Anh