The strong cold air mass is about to affect the North and Central regions, causing many dangerous types of weather. Mr. Nguyen Van Huong - Head of Weather Forecast Department, National Center for Hydro-Meteorological Forecasting - provided the latest comments on this northeast monsoon.
Sir, is it possible that this strong cold air mass will experience particularly heavy rain like in October 2025?
- Regarding the impact of this heavy rain, there are many similarities compared to the record heavy rain lasting from October 25 to 30, which was also affected by cold air, strong easterly winds at an altitude of 1,500-5,000m and low pressure trough with an axis passing through the Central region.
According to our assessment, in this heavy rain, there are 2 factors that are not as strong as the previous one, which are the weak winter wind, the low pressure trough is not as strong as the 25 - 30 October.
The characteristic of this heavy rain is that the heavy rain area has fluctuations. From November 15 to tomorrow, November 18, the rain will extend from Ha Tinh to Quang Ngai, the eastern area of Gia Lai province, Dak Lak and Khanh Hoa area.
However, from November 19, the rain in the provinces from Hue will tend to decrease, while the rain will tend to widen to the south.
The rain is not concentrated in one area, so although the cold air of this period is much stronger than at the end of October, the possibility of especially heavy rain or record rain like the rain in the last days of October is not high.
Thus, this rain will last and the heavy rain will spread. So, what is the risk of flooding on rivers in the Central region and which areas are most worrying about landslides, flash floods and inundation, sir?
- This heavy rain will spread across most of the Central provinces and cities, so many rivers in the Central region will also be affected, it is forecasted from today until November 20. There is a possibility of a flood on rivers from Ha Tinh to Khanh Hoa.
During this flood, the peak flood in Hue city, Da Nang city; Quang Ngai; Kon river, upstream of Ba river (Gia Lai), downstream of Ba river, Ky Lo river (Dak Lak), Dinh Ninh Hoa river (Khanh Hoa) may increase to alert level 2 - alert level 3, some rivers above alert level 3; Ha Tinh river, Quang Tri river, rivers in Gia Lai, rivers in Dak Lak, rivers in Khanh Hoa are likely to increase to alert level 1 - alert level 2 and above alert level 2.
In addition to rising flood waters on rivers, during this heavy rain, we should note that in addition to areas with heavy rain, risk of flooding, flash floods, and landslides in the area from Ha Tinh to the east of Quang Ngai province, we should note that Quang Ngai, Dak Lak, Khanh Hoa area as well as the east of Lam Dong province are also areas that need special attention to the risk of flash floods and landslides because these areas will continue to have long-term rain.
How does strong cold air affect the weather in the North? Is there a possibility of frost and frost during this cold spell, sir?
- It can be confirmed that this is the coldest period of intensity since the beginning of winter. According to our observations, the air pressure in the cold air mass will reach 1075mb; the central ear temperature will drop below minus 30 degrees; the direction of this cold air mass will go north-south, straight down from the north.
In addition to strong cold air, straight to the north, from tonight to the end of November 19, the North will also have more rain. Rain combined with strong cold air will cause the temperature in the North, Thanh Hoa, Nghe An, and Ha Tinh to drop sharply.
According to our assessment, November 18 - 19 will be the 2 coldest days with the lowest temperature in the Northern Delta and North Central regions generally from 12-14 degrees Celsius, in mountainous areas from 8-11 degrees Celsius, in high mountainous areas below 7 degrees Celsius.
From November 20, the rain in the North will decrease and will turn to a state of deep cold at night and in the morning, sunny during the day; and the conditions for frost must be limited to light clouds at night, so the possibility of frost appearing in the first 2 days is not high. But the period from November 20 to 22 is possible, especially in the mountainous and midland areas of the north.
Sincerely thank you!
