Beware of the violent spring wind - Looking northwest, we see the wolf

1. Gentle Spring Breeze VS Violent Spring Breeze

1. Differences in Spring Breeze

When people think of spring breeze, what comes to mind are probably the warm sunshine and the warm east wind. This is also common in ancient poems. Typical and well-known ones include "The year is coming to an end and the frost is less. Spring has come to the world and the plants and trees know it. I feel that my eyes are full of life, and the east wind blows the water green." (Occasionally written by Zhang Zai in the Song Dynasty), "The east wind blows away the snow on the branches of plum trees, and spring is restored overnight. From now on, spring should have its feet, and all flowers are rich and the grass is full of vigor." (Beginning of Spring - Song Dynasty - Bai Yuchan), "I don't know who cuts the fine leaves, the spring breeze in February is like a pair of scissors" (Ode to Willow - Tang Dynasty - He Zhizhang), etc. There are so many poems about spring breeze, almost all of which are about warming and spring. Even Zhu Ziqing's prose "Spring" begins with the first sentence "Looking forward to it, looking forward to it, the east wind is coming, and the footsteps of spring are approaching."

Indeed, in many cases, spring breeze symbolizes the passing of winter and the coming of spring, the return of warmth and the revival of all things, especially in the Central Plains and the areas to the south. But in northern my country, this is not necessarily the case. Spring breeze has more two-sidedness: when cold air comes, spring breeze means violent sandstorms, and it only shows a gentle side when the cold air passes and the temperature rises. In the north, cold air is very fierce when it first arrives, usually in the front of the cold high-pressure system, mostly northerly winds, and will quickly weaken after moving south and east into the sea. The areas south of the Central Plains are in the easterly and southerly winds behind the cold high pressure entering the sea, which are the gentle spring breezes and easterly winds.

Surface weather map at 02:00 on April 27, 2023 (high pressure wind direction circulates clockwise, low pressure wind direction circulates counterclockwise)

Average wind (left) and gusts (right) over the past 24 hours at 13:00 on April 27, 2023

Temperature changes in the past 24 hours at 13:00 on April 27, 2023

2. Accompanied by wind and sand

Since April, cold air activities have been more frequent and stronger. Not only has the temperature in the north changed from significantly higher in March to lower in April, but there has also been a lot of wind and sandstorms. The number and impact of sandstorms have exceeded the peak in the past 10 years and reached the level of many years in the past 20 years. It is becoming normal for the north to "eat dirt" (up to now, the Central Meteorological Observatory has counted 10 sandstorms, including one sandstorm and two strong sandstorms).

Comparison of the average temperatures in March (left) and April (right) across the country with those in normal years

Statistics of sandstorm weather processes across the country from 2003 to 2023 (Central Meteorological Observatory)

The latest sandstorm weather forecast from the Central Meteorological Observatory

The main characteristics of the weather in the north in the next few days will still be windy and sandy, with fluctuating temperatures. There will also be rain and snow in the northeast, which is very lively. But what I am most concerned about is the strong winds. The large-scale strong winds are like a sharp arrow that has been strung in northern Xinjiang, drawn, aimed at the northwest, and will go straight into the Central Plains. 2. A spring wind arrow shot towards Shaanxi, Gansu, Ningxia, Inner Mongolia, Shanxi and Henan. Since this morning (April 27), strong winds have continued to occur in northeastern Xinjiang and western Mongolia and Gansu. Gusts above level 10 have appeared not only in the mountain passes but also in the lowlands.

Maximum wind gust observed in one hour at 14:00 on April 27, 2023 (left>8; right>10)

In the future, the core area of ​​strong winds will be transmitted to the southeast, and the transmission speed is slower than the wind speed. Its affected area will gradually increase. Although its wind force level is affected by sunrise and sunset, its core area of ​​strong winds is not affected by daily changes (spring strong winds are usually stronger during the day than at night on sunny days). It is expected that the core area of ​​strong winds will still be located around the eastern part of Xinjiang in the first half of the night, and will reach the southwestern Inner Mongolia and central Gansu in the second half of the night and the morning of the 28th. During the day on the 28th, Shaanxi, Gansu and Ningxia will be the core area, with the strongest wind force. The maximum gusts will exceed level 10 in many places, and it is possible to reach level 11 or even level 12. At night on the 28th, the strong wind range will spread to Shanxi, Henan, Hebei, Anhui, Hubei and other places, and the maximum gusts will be reduced to about level 7-8.

Summary of the evolution of key high wind areas from the night of April 27 to the night of April 28, 2023

Since the wind is very strong and coming from the northwest, there will be sandstorms along with this wind. As mentioned before, in the north, sandstorms in spring are very common, especially this year. So why did this wind attract my attention? I wanted to explain it briefly, but considering some of the things I want to say, it would be difficult to explain clearly: it is somewhat controversial within the profession; it is very unfriendly to people outside the profession; it is too late for today; and it cannot be published today due to the timeliness of the weather in this article. So let's stop here.

3. Matters needing attention

There are many precautions to take in windy weather.

From the perspective of personal safety: residential buildings should pay attention to falling objects (reinforce what needs to be reinforced, demolish what needs to be demolished, and retract what needs to be retracted); pay attention to the increased wind force caused by various narrow channel effects, and reduce going out; suspend all outdoor high-altitude operations; suspend water activities and operations; when avoiding the wind, also pay attention to damage from various unstable fences, billboards, scaffolding, etc., and be careful not to stand under dangerous walls, etc.

From the perspective of agricultural production: agricultural facilities such as greenhouses may need to be reinforced, or closed to reduce exposure to wind. I am not sure whether there will be any damage to fruit trees in the northwest region. Perhaps not much. For winter wheat in the affected areas, it is in the stages of jointing, heading, heading, and flowering. The center of gravity has not moved up and there is wind but no rain. Probably there is no need to worry about lodging. I am ashamed to say that there are many things I don't understand.

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