What's the weather like before and after strong cold air crossing the border?

Before the cold front crosses the border: it is controlled by a separate warm air mass.

High temperature, clear weather and low air pressure;

When crossing the border: strong wind, cooling, rainy (precipitation is concentrated behind the front, but also before the front)

;

After the cold front:

1, temperature: drop

2. Air pressure: decrease first and then increase.

3. Precipitation: There is rain behind the front.

4. Weather: It will clear up.