What is the Northeast Cold Vortex?

"It started snowing again in April", "I'm in Harbin, and the roof of my house is about to be blown off", "I put on the down jacket I just took off again"...

During the Qingming Festival, my country's Northeast region experienced a variety of weather types, including severe temperature drops, strong winds, rain, snow, and even local sandstorms. What caused such a "rich" weather to appear in the same period? It was the Northeast Cold Vortex.

What is the Northeast Cold Vortex?

A cold vortex, or "cold low vortex", is a "low vortex with a central temperature lower than the surrounding areas at the same height" from high latitudes. According to the monitoring standards for the Northeast Cold Vortex, a cold vortex that appears at 35°-60°N and 105°-145°E and lasts for more than 3 days is called the Northeast Cold Vortex. The Northeast Cold Vortex is one of the main weather systems affecting the central and eastern regions of my country.

Sun Jun, chief forecaster of the Central Meteorological Observatory, introduced that the cold vortex system has distinct characteristics on satellite cloud images, often presenting an asymmetric vortex structure with a huge scale. The extended cold front cloud system can sometimes be as long as several thousand kilometers.

The Northeast Cold Vortex can be seen all year round, and is most active in the summer. Its life cycle is an average of 3 to 4 days, and can be as long as 19 days. Statistics show that in the Northeast, the most thunderstorms are caused by the Northeast Cold Vortex. In addition, 64% of squall lines are related to the cold vortex process. The hail caused by the cold vortex accounts for nearly half of the total number of hail days in the Northeast.

What are the weather characteristics of the Northeast Cold Vortex?

Sun Jun introduced that one of the weather characteristics of the Northeast Cold Vortex is that although the cold vortex system itself is more active in Northeast my country, Russia, Mongolia and other places, its impact range is far beyond the center of the low vortex. Taking the impact of the cold vortex system on April 6 as an example, in addition to bringing heavy snow to the northern part of Heilongjiang near the system, it also brought convective weather such as small hail to the local area of ​​Henan. The extreme wind weather in Nantong, Jiangsu on April 30 last year was also caused by the background of the Northeast Cold Vortex.

Another major weather feature of the Northeast Cold Vortex is that the weather it produces is complex and diverse. Weather such as heavy rain, heavy snow, strong winds, cooling, sandstorms, and severe convection can occur at the same time or some of them can occur. Sometimes the weather it produces is extreme. The strong sandstorm weather that affected Beijing on March 15 last year was caused by the background of the Northeast Cold Vortex.

Who else are there in the Lengwo family?

Sun Jun introduced that a cold vortex usually refers to a large vortex system existing in the high altitude, which rotates cyclonically and generally exists in mid- and high-latitude regions. When it develops and matures, the area near its center is accompanied by thick cold air, so it is called a high-altitude cold vortex.

Sun Jun said that depending on the location where it appears, it will have different names. The high-altitude cold vortexes that affect my country generally include the Northeast Cold Vortex, the Mongolian Cold Vortex, the North China Cold Vortex, etc.

What does this have to do with the cold wave?

Sun Jun pointed out that during the eastward movement of the high-altitude cold vortex, the ground is often accompanied by cold air moving eastward and southward. When the cold air is strong, it can form a cold wave, affecting most parts of my country. In other words, cold waves are one of the weather that may be brought by the high-altitude cold vortex.

Recently, the Central Meteorological Observatory, Shenyang Central Meteorological Observatory, and Northeast Cold Vortex Research Key Open Laboratory jointly released the first issue of the "Northeast Cold Vortex Monitoring and Forecast Bulletin" (hereinafter referred to as the Bulletin). It is understood that in the first issue of the Bulletin, there are not only the past path, intensity and 96-hour path forecast maps of the cold vortex system itself, but also real-time monitoring information on the weather under the influence of the cold vortex, forecasts of weather such as precipitation, severe convection, strong winds and cooling in the background of the cold vortex in the next 24 hours, weather trend forecasts for the next 48 to 72 hours, and related defense recommendations.

Editor: Zhai Qiaohong

Editor: Zhao Wen

Source: People's Daily Online reporters Li Nanhua and Wen Lu