Spring is the season of recovery, but also the season of changeable weather, in the past last week, this characteristic was manifested in the north and south of the mainland - on April 19, a strong cold air suddenly hit, causing the temperature in many places in the north to plummet, some areas saw a large temperature of more than 20 degrees, and even a rare snowfall phenomenon.
First, the Siberian cold vortex struck again
For example, Baiyun Obo in Inner Mongolia, when the temperature dropped sharply by more than 20 degrees, Baiyun Obo gradually turned from rain to snowfall, and in the monitoring data of the weather station on April 19, the snowfall at only 9~15 o'clock was close to the level of blizzard. In addition to Inner Mongolia, Taibai Mountain in Shaanxi Province and Chengde Enclosure in northern Hebei Province also reported that the local temperature dropped sharply, and snowfall occurred in some areas, directly returning to the winter scene.
In the new week, it is here again, and it is more violent, and it will strongly affect the north, and it will also cause strong convection, thunderstorms, hail and other intense weather that will overwhelm people. Supercomputer forecasts indicate that the weather in the northern part of the continent is becoming more intense as the over-amplitude westerly wind belt continues to push the cold vortex southward from Siberia.
Second, a large-scale thunderstorm in the north is confirmed!
The Central Meteorological Observatory will continue to issue a blue warning for strong convective weather at 10 o'clock on April 22, and it is expected that from 14 o'clock on April 22 to 14 o'clock on the 23rd, there will be 8-10 thunderstorms and strong winds or hail weather in parts of central and southern Hebei, southern Tianjin, central and northern Shandong, northern Henan, eastern Fujian, southeastern Guangxi, and central and southern Guangdong, with local winds up to 11; Some areas in Guangdong and other places will have short-term heavy precipitation weather, with a maximum hourly rainfall of 30-50 mm, and locally up to more than 70 mm. This means that while the strong convection and heavy rains continue in the south, there are more places in the north with thunderstorms, strong winds and hail, which is typical of cold vortex thunderstorms in spring and summer.
The Central Meteorological Observatory pointed out that under the influence of the cold vortex, there will be a wide range of rain in the northeast of North China and Huanghuai, and moderate to heavy rain can be reached in many places, and from April 22 to April 23, the eastern part of Hebei and the western part of Liaoning can reach the level of heavy rain, showing that this thunderstorm is not only dense with thunderstorms, strong winds and hail, but also heavy rain in some areas.
What is the Siberian cold vortex? It is a high-altitude cyclonic vortex from the middle and high latitudes, which has deep cold air inside, and the central pressure is lower than the surrounding area, showing the characteristics of a cold core. Its formation and development are mainly influenced by the westerly wind belt. The westerly wind belt is a prevailing wind blowing from west to east in the mid-latitudes, blowing from the high pressure area of the subtropical high pressure belt to the polar region. Fluctuations often occur in the westerly wind belt, forming troughs (low pressure) and ridges (high pressure). The trough line in the westerly wind belt is called the westerly trough. The westerly trough is a strong dynamic system, and sometimes, under certain conditions, its southern end will gradually cut off, so as to break away from the westerly wind belt and form an independent vortex, which is the process of cold vortex formation.
Cold vortex thunderstorm refers to the thunderstorm weather formed by the strong convective movement due to the meeting of cold air and warm and humid air currents under the control of cold vortex. Cold vortex thunderstorms are characterized by wide range, short duration, high intensity, rapid change and complex impact. Cold vortex thunderstorms are often accompanied by wind, hail, tornadoes and other disastrous weather, causing serious harm to people's production and life.
A cold vortex thunderstorm in April 2023
3. Locally or also snowing
It is worth noting that the cold vortex that has recently split southward is very strong, and the cold air brought by it is very strong. For example, after last week's cold vortex brought snowfall to Inner Mongolia and Hebei, the cold vortex that is moving south to the mainland may also bring snowflakes - supercomputer simulation forecasts point out that in the early morning of April 23, under the influence of cold vortex and cold air, snowflakes will fall in some parts of Inner Mongolia and Hebei.
According to the forecast of the Central Meteorological Observatory, the influence of the Siberian cold vortex will gradually move eastward in the northern part of the continent from 23 to 25 April, and will begin to affect more places in the northeast plain from 24 April.
After April 24, the cold vortex thunderstorms in the northern part of the mainland will gradually weaken, and the precipitation and severe convective weather in the northern part of the mainland will gradually decrease when the cold vortex weakens and dissipates. However, the supercomputer forecast also pointed out that from April 26, another cold vortex will split southward from Siberia, bringing a new round of cold air to the north of the continent, and some areas may usher in rain again.
In short, the Siberian cold vortex is a powerful and complex weather system, which has brought obvious changes and impacts to the weather stage in the north of the continent, and will also bring a lot of troubles and troubles to people's lives. Everyone should pay close attention to the early warning information of the meteorological department and take preventive measures in time. In particular, the cold vortex will cause thunderstorms, strong winds, hail, tornadoes and other strong convective weather, which will pose a threat to the safety of life and property, and everyone needs to be vigilant and pay attention to safety and avoidance.