How strong is the level 8 wind?

The 8-level wind is called strong wind, the twigs of trees can be broken, and people walk against the wind with great resistance. Grade 8 wind refers to Beaufort wind, with a wind speed of 17.2-20.7 m/s, equivalent to 62-74 km/h ... Fishing boats take shelter from the wind in the harbor, and the huge waves gradually rise, and the peaks are broken, and the waves are obviously blown into strips with the wind.

Level 0 wind is also called no wind. Level 2 wind is called breeze, the leaves are slightly noisy, and people feel windy. Level 4 wind is called breeze, and the twigs of trees shake, which can blow up dust and paper on the ground. The 6-level wind is called strong wind, the branches are shaking, the wires are whistling, and it is difficult to walk with an umbrella. 10 wind is called gale, which is rare on land. Trees can be pulled up and buildings are seriously damaged. Winds above 12 are called typhoons or hurricanes, which are extremely destructive and rarely seen on land.

Extended data

Based on the NCEP grid analysis data and conventional observation data, the physical mechanism of the 8-magnitude gale process caused by the cold wave in Guangdong on June 4 ~ 7, 2006 is analyzed. The results show that, influenced by the southward movement of strong cold air, there is a deep advection of strong cold air, and at the same time, there is a strong wind of magnitude 8 in eastern Guangdong and western Guangdong.

This provides a good foundation for more accurately forecasting the gale in Guangdong sea in the future.

The collapse of Ω blocking high formed at Ural Mountain 1 and 500hPa indicates that the cold wave started to break out to the south, and the transverse trough swung down completely, indicating that the adjustment of the upper-air circulation situation was basically completed.

2. The strong cold air from east to west has different characteristics. The cold front in the east moves fast, the cold layer is thick and the cold advection is strong, and there is a downward transfer of high-altitude momentum behind the cold front. Therefore, when the ground cold front crosses the border, Shantou will soon have a northeast wind with 8 gusts and 9 grades.

The cold air on the west road is shallow in front of the cold air front, so there is a strong wind on the sea surface in western Guangdong when the front crosses the border, but it is not strong. Then the cold air supplements, the cold air layer thickens, the cold advection intensifies, and the momentum of the upper air is transmitted downwards, so the wind force on the sea surface in western Guangdong increases obviously, and finally the northerly wind of gust 10 appears.

3. By analyzing the horizontal and vertical directions of cold advection, it can be clearly seen that the strong cold advection transport and the * * * interaction from high altitude momentum caused the gale of magnitude 8 in Guangdong Sea, which provided a good basis for better forecasting the gale of magnitude 8 in the sea caused by the southward movement of strong cold air in the future.

Baidu Encyclopedia-Level of Wind

Baidu Encyclopedia-Level 8 Wind