Almost 10 days ago, when we talked about a cold wave, we also had a rough survey of the weather during the critical period of the Spring Festival in early February, when it was considered that if the south branch trough continued to be active, there would be a wide range of rain and snow in the south.
Starting from the 31st, the central and eastern regions of China will encounter the largest and longest rain and snow weather process since this winter, which will also be the most complicated Spring Festival weather since 2008. Today and tomorrow, it is still dominated by widespread rainfall in the south and snowfall in the northeast, and the cold air will move south on the 31st, and a wide range of rain and snow will appear, and the temperature in most parts of the central and eastern regions will gradually turn low, and the rain and snow dividing line will gradually press south to the line of eastern Guizhou - northern Hunan - eastern Hubei - northern Jiangsu and Anhui.
The area north of this rain-snow dividing line has mostly moderate to heavy snow, some areas of heavy snow or even heavy snow, and the south area has moderate to heavy rain, localized heavy rain, accompanied by a wide range of thunder and lightning. February 2-4 is the heaviest period of snowfall.
Specifically: **The Meteorological Observatory predicts that from January 31 to February 5, there will be snowfall in the eastern part of Northwest China, North China, Northeast China, Huanghuai and other places, Jianghan, western and northern Jianghuai, northwest Hunan, central and northern Guizhou and other places, moderate to heavy snow in most of the above areas, blizzard in some areas, local heavy snowfall or extremely heavy snow; There was moderate to heavy rain in most areas of the middle and lower reaches of the Yangtze River and south of the Yangtze River, and heavy rain in some areas. From February 1 to 4, there was freezing rain in parts of southern Henan, Hubei, central and northern Anhui, northern Jiangsu, southern Shandong, central and northern Hunan, and eastern Guizhou.
According to meteorological experts, the rain and snow weather is mainly due to the superposition of the south branch trough and the north branch trough, which is conducive to the southwest warm and humid airflow to the north, bringing a wide range of rain and snow weather. The process has the characteristics of wide rain and snow coverage, long duration, large range of freezing rain, and extreme cumulative precipitation in some areas.
The most complicated Spring Festival weather since 2008.
The complexity of the rain and snow process is reflected in the complex switching of precipitation phase and rain and snow transition. Judging from the current forecast, the middle and lower reaches of the Yangtze River and the south of the Yangtze River are mainly rainfall, and there is a large range of thunder and lightning activities. The northern region will experience rain and snow transformation, especially in the central and eastern parts of the country on the 3-4th day, the heavy snowfall will be very large, and there may even be a local heavy snowstorm; At the same time, there is also a wide range of freezing rain in some areas. Not only that, Jianghan, western Jianghuai, western Hunan, eastern Guizhou and other places may also have frequent transitions between rain and snow, and the phase is very complex.
Beginning on the night of February 1, the snowfall expanded and intensified. The complexity is also reflected in the wide range of freezing rain. This will be the most freezing rain in provinces since this winter, with freezing rain in parts of southern Henan, Hubei, northern Anhui, central and northern Hunan, and eastern Guizhou from February 1 to 4.
Heavy snowfall areas are still likely to be adjusted, which is also the complexity of this process. Zhang Juan, a meteorological analyst at China Weather Network, said that the reason why the rain and snow process was strong this time was that the water vapor conditions were very good: due to the northerly position of the subtropical high, the southwestern warm and humid airflow and the southerly water vapor continued to move northward along the water vapor channel and the edge of the subtropical high in the southern branch trough. On the other hand, the dynamic conditions of precipitation are also very suitable: the high altitude has the joint influence of the south branch trough and the north branch trough, and forms a deeper high-altitude trough in the later stage, which is more conducive to the occurrence of large-scale snowfall.
Therefore, from the perspective of the weather situation, it is clear that there is a wide range of rain and snow, and the intensity is still very strong, but at present, there are some differences in the development and future path of the Jianghuai cyclone. Especially after the 2nd, there is still a possibility of adjustment in the heavy snowfall area after the Jianghuai cyclone moves north. However, overall, Henan and Shandong are likely to be the epicenter of heavy snowfall, and if the Jianghuai cyclone goes all the way north and is located northward, then the Northeast region also needs to pay attention to heavy snowfall.
Rain and snow are widespread, have a long impact time, and have a risk of disaster.
The rain and snow cover a large area, basically covering the entire central and eastern regions, of which the cumulative snowfall in Henan, Shandong, and Hubei is close to or exceeds the same period in history, which is extreme.
Rain and snow lasted for a long time, starting on January 31 and lasting for six days in the central and eastern regions, from January 31 to February 5. Among them, the snowfall period in some places such as Henan and Hubei can last for 4-5 days, such as Xuchang, Nanyang, Henan, Xiangyang, Hubei and other places. In addition, after February 7, the weather in the northern part of the Yangtze River and most of the areas north of the Yangtze River became clear, but there were still frequent rainy and snowy weather in the eastern part of the southwest region, the southern part of the Yangtze River, and the southern part of the country.
Why did the rain and snow last so long? Zhang Juan explained that it was mainly because of the "tug-of-war" between the cold and warm forces. On the 31st, the strength of cold air in China is not very strong, and there is continuous cold air replenishment in the later period, at the same time, water vapor is also endless, and the cold and warm air forces are equal, forming a confrontation situation, thus causing long-term and large-scale rain and snow weather. On the contrary, if the cold air is strong, like the last cold wave, it will push the rain and snow southward quickly, and the impact will not last long.
Rain, snow and ice affect the way home for the Spring Festival.
It's not that there hasn't been stronger rain and snow in the past, but the core problem of this rain and snow is that it will affect the Spring Festival. Previously, the relevant departments predicted that there will be 9 billion people during the Spring Festival this year, and the total number of commercial passenger traffic such as railways, highways, waterways, and civil aviation will exceed 1.8 billion, a year-on-year increase of about 40%, and the three data have hit a record high, which can be called the "busiest" Spring Festival in history.
In terms of time period, the impact of rain and snow from the middle and late part of this week to the beginning of next week is the critical period of the Spring Festival; From a regional point of view, regardless of the changes in the heavy snowfall area after that, the core area affected by rain and snow includes central regions such as Hubei and Henan, and these areas are the transportation hubs connecting the north and south of China and the east and west.
The last time there was an impressive large-scale rain, snow and freezing weather during the Spring Festival was the overlord-level cold wave in 2016, and further back, it was the rain, snow and freezing low temperature disaster process in the south in early 2008. Fortunately, according to the current forecast, this year will not encounter such extreme conditions as in 2008, ** The meteorological observatory predicts that the duration, low temperature intensity, and freezing range of this rain and snow freezing are not as good as in 2008.
The good news is that after the 7th, the weather in the north of the middle and lower reaches of the Yangtze River will become clearer, and the weather will be much calmer on the way home.