How to judge the wind direction in the weather system diagram

First determine whether it is high pressure or low pressure, southern hemisphere or northern hemisphere.

After confirmation, high pressure and wind blow outward from the high pressure center. In the northern hemisphere, use your right hand (because the geostrophic force is to the right), palm up, palm root at the center of air pressure, fingertips outward, thumb naturally open, and the direction of thumb is the wind direction.

Low pressure, wind blowing from the outside to the center. In the northern hemisphere, the right hand (because the ground turns to the right), palm up, palm root out, fingertips pointing to the air pressure center, thumb naturally open, thumb pointing to the wind.

Generally speaking, the weather system is represented by isobars, which are basically in a circle, and the wind direction in each direction in the circle is different. Generally, a point a or b will be given. To find the wind direction in these areas, just put your palm on point A or point B, and your thumb will open naturally, so you can determine the wind direction according to the direction of your thumb.

The southern hemisphere uses the left hand for the same reason as above.

In fact, you just need to imagine raising your palm like that, and you will know the position of your thumb in your heart. You don't really need to hold your palm to do it.

Principle: the geostrophic force affects the wind direction, such as high pressure, the wind blows from the outside to the center, the arrow points from the outside to the inside, and the geostrophic force in the northern hemisphere is like the right. On the basis of the original arrow, the wind direction can be drawn by shifting to the right. The right hand is used because the thumb of this hand is just on the right side of the palm.