How to read the wind direction such as F in the wind vane? What is the wind direction when F tilts 45 to the right?

F is the north wind, level 4; F inclined 45 to the right is northeast wind, level 4.

The arrow of the weather vane always points to the source of the wind. Its principle is that the wind area of the arrow tail is larger than that of the arrow. If both the arrow and the arrow tail are affected by the wind, then the arrow tail will be pushed back by the wind, making the arrow move towards the source of the wind.

Extended data:

1. Interpretation method of wind vane: it is expressed by wind vector and consists of wind stem and wind plume.

Wind feather: 3 or 4 short strokes and triangles indicate strong wind, perpendicular to the right side of the wind pole (northern hemisphere).

1- secondary: 1 vertical line 1 horizontal line

Grade 3-4: 1 vertical line and 2 horizontal lines

Grade 5-6: 1 vertical bar 3 horizontal bar

Grade 7-8: 1 vertical bar 4 horizontal bar.

Above level 8: 1 vertical bar 1 triangle is like a small flag.

2. Wind vane (wind? Wind vane is an instrument for measuring wind direction. Generally, it is installed on a telephone pole with openings around it, which is about 10 meters high from the ground. Under the action of wind pressure, the wind vane arrow refers to the direction of the wind. Generally, it will be divided into three parts: head, horizontal bar and tail.

References:

Baidu encyclopedia-wind vane