How to define several wind speeds in weather forecast?

Strictly speaking, the wind speed level should be called the wind level. We can understand this word in two parts. The first is wind power generation. What is wind power? Literally, we can understand that wind refers to the strength of the wind blowing on an object. Grades are generally classified according to the visible phenomena produced by wind on objects, and are generally divided into 18, that is, 0- 17, with the smallest being 0 and the largest being 17.

Wind speed and wind speed are two different concepts. Wind speed refers to the forward speed of wind, which is related to air pressure. Generally speaking, the greater the pressure difference between two adjacent objects, the faster the airflow, which means the greater the wind speed, and of course the greater the wind power. Therefore, the size of the wind is expressed by the wind force.

So how is the wind measured?

For the accuracy of measurement, people often use portable anemometers to measure outdoor wind. This portable anemometer generally consists of a sensing part and a counter. The induction part consists of three air cups (there are also four air cups) installed on the cross. The air cups can rotate freely on bearings and are protected by a small frame. The lower part of the central shaft is connected with the counter, and when the air cup rotates, the counter also rotates. So the counter records the number of revolutions of the air cup.

Wind speed anemometer

Portable anemometers are generally placed in open areas around without tall obstacles, and their bodies are vertical. Turn off the switch before observation and write down the instructions of the pointer. After a minute or two, turn on the switch and start the stopwatch to record the time. At this point, the observer quickly left the anemometer and stood downwind of the instrument. After starting the instrument for nearly 100 seconds, the observer quickly approaches the instrument, turns off the switch at 100 seconds, and records the indication of the second hand. According to the two readings before and after, calculate the difference value, indicating the scale number of anemometer pointer during the observation time, and record it in the record table.

For the accuracy of measurement, it is usually measured several times and then averaged to reduce the instrument itself and human error.