According to the National Center for Hydro-Meteorological Forecasting, the cold air mass is still moving south.
From the afternoon and night of December 10, due to the influence of cold air combined with high-altitude easterly wind disturbances, the Central Central and South Central regions will have moderate rain, heavy rain and thunderstorms, with some places experiencing very heavy rain. Thunderstorms may include tornadoes, lightning and strong gusts of wind.
Heavy rain can cause flooding in low-lying areas; flash floods in small rivers and streams, and landslides on steep slopes.
Around the afternoon and night of December 11, this cold air mass will affect the northeastern provinces, then affect the North Central region and some places in the northwest. The northern region will turn cold, with some mountainous areas experiencing severe cold.
The lowest temperature in the North on December 11 is about 15 - 18 degrees Celsius, in mountainous areas 13 - 15 degrees Celsius, in high mountainous areas some places below 13 degrees Celsius. The average temperature is about 19 - 21 degrees Celsius; in mountainous areas 15 - 18 degrees Celsius, in some places below 14 degrees Celsius.
Hanoi area on December 11 will have light rain at times; from the evening and night of December 11, the weather will turn cold. The lowest temperature in this cold air mass is commonly 15 - 17 degrees Celsius.
From the night of December 12, cold air continues to strengthen and affect the Northwest, Central Central and some places in the South Central. The wind changes to the northeast, strong level 3 inland, level 3-4 in coastal areas.
The weather in the North Central region is turning cold. The lowest temperature in this cold air mass in the North and North Central regions is generally from 14 - 17 degrees Celsius, in mountainous areas 11 - 14 degrees Celsius, in high mountainous areas, some places are below 10 degrees Celsius.
At sea, from the evening and night of December 11, the wind in the Gulf of Tonkin will change to strong northeast level 6, gusting to level 7-8; from the night of December 12, the wind will gradually increase to level 6-7, gusting to level 8-9; the sea will be rough; waves will be 2-3m high.
From the evening and night of December 11, in the North East Sea area (including Hoang Sa archipelago), the northeast wind will gradually increase to level 6 - 7, gusting to level 8 - 9; rough seas; waves 3 - 5m high.
Strong winds and large waves at sea are likely to affect boating and other activities.
