Why does the north wind or northwest wind blow more often in the north of my country in winter?

Winter is the season when the cold air from Siberia moves southward, with northerly or northwesterly winds blowing. The flow of air forms wind, which is warm in the south and cold in the north. Warm and cold air must convection, so northwest wind or north wind will blow.

There are two main causes of northwest wind in my country. The first is the winter monsoon generated by the Mongolian-Siberian high, which will blow northwest winds. The second is that the westerly wind in the westerly belt is deflected to the right by the geostrophic deflection force to form a northwest wind (this is also the primary cause of the northwest wind in the northern hemisphere latitude 30-60 degrees), especially the westerly wind from Western Europe because it is less affected by high altitudes. Terrain obstruction has a great impact on northwest my country.

Other northwest winds are basically caused by uneven heating of the atmosphere and different local air pressures, and are somewhat accidental.

Extended information:

The Siberian high pressure often invades my country under the guidance of upper air flow. From autumn to winter, the scope of influence gradually expands from north to south. The powerful Siberian high pressure front in winter can affect the South China Sea, the Philippines, and the Ryukyu Islands; in spring, the force weakens, and the scope of influence shrinks from south to north; in summer, it rarely affects my country.

The moving speed of the Siberian High is relatively high when it first moves away from its source, and then gradually becomes smaller. In mountains and hilly areas, it moves slower; in plains and seas, it moves faster.

According to the moving path of the Siberian high pressure and the ground situation map, it can be seen that when the high pressure moves southward, three types of weather can occur along the coast: first, the cold front weather comes at the front, then the high pressure center weather, and finally The high pressure may be whole or split into several small high pressures and move eastward into the sea one after another. The coastal areas are controlled by the weather at the rear of the high pressure. At this time, the cold front weather at the front of the new Siberian high pressure is coming again.

The periodic activity of the Siberian High is the main feature of weather changes in winter and spring. The interval between two cold fronts is about 7-10 days, and in spring it is about 3-5 days.