To put it simply, you can take your down jacket out at the bottom of the box. If necessary, and there is no stark raving mad in the Double Eleven, you can buy a big goose. If you lose your mind, you can wear two down jackets.
Next, we will introduce the relevant situation of this cold wave from the following aspects:
(1) Start-End Time/Range
It is predicted that this cold wave will start on the night of 2021.1.4, and will first affect the northern part of Xinjiang. 5 will continue to invade the southeast, but the spread is still concentrated in the northwest of China. On the 6th, a cold wave will invade heavily, and most parts of North China and Central China will be swept by strong cold air. On the 7th, cold air arrived in the south of China.
In other words, starting from the 6th, most parts of China will face the situation of overnight winter. The cold air force of this cold wave is strong, and the process cooling brought about is expected to be comparable to that in 2008.
(2) Causes
In winter, the temperature in the Arctic and Siberia can be below minus 20 degrees. A large amount of cold air gathers in these places, forming a high cold air pile (cold high pressure). Under the suitable atmospheric circulation background (such as the formation of high pressure ridge), it will invade southward and form cold wave weather.
The main reason for the formation of this cold wave is that the cold wave and cold high pressure moved eastward and southward from the Mongolian Plateau, bringing a lot of cold air to the north of China.
Coupled with the eastward movement of the 500-hectopascal trough, the westerly trough moves eastward, transporting a large amount of cold air to the south, thus forming a cut-off vortex (simply storing cold air in a closed air mass).
Because this vortex is deep and involves a wide range, and the whole vortex rotates counterclockwise, a large amount of water vapor in Bohai Sea and Japan Sea is transported to Inner Mongolia and Northeast China. If there are good terrain conditions and dynamic uplift, snowfall can be formed in these places (temperature and water vapor conditions are met at the same time).
(3) weather conditions.
Some areas with sufficient water vapor content may see the first snow this year, while some areas with insufficient water vapor content may only cool down. Because some roads may have accumulated water, the transportation department should take relevant measures to prevent slippery roads.
It should be noted that since all kinds of colds are prevalent in different seasons, it is best to take warm-keeping measures in time to avoid making the unhealthy body worse because of this cold wave activity.