On May 11, as the westerly wind belt violently oscillated, the southward movement of the cold vortex induced an extratropical cyclone in the northern part of the continent, which can be seen on satellite cloud images as a "typhoon" after landfall. With the emergence of the cyclone system, moderate to heavy rain and localized heavy rain fell in eastern Inner Mongolia and most of Heilongjiang from yesterday to today, and the rain belt on the south side of the cyclone has been thrown southward.
1. It is very hot at 45 degrees in the north
And with the extratropical cyclone activity, there has been a wide range of cooling in the central and eastern parts of the mainland today, and the 24-hour temperature change map can be seen on the blue-purple cooling zone from Northeast China to the Huanghuai and Yangtze River basins, and some stations have a 24-hour cooling range of more than 10 degrees.
On May 11, the high temperature weather on the mainland has shown signs of intensification - when many places in the eastern part of the mainland are under the influence of cold vortex and cold air, the temperature in the western region has begun to skyrocket, and it can be seen on the 6-hour maximum temperature list that many places in Xinjiang have replaced Hainan and Yunnan, completely dominating the list, and the temperature in Turpan has exceeded 40 degrees at both stations.
In fact, according to the forecast of the supercomputer, the northern part of the mainland will usher in a wave of fierce hot and dry weather in the middle of the year, especially in the Turpan Basin in the inland of Xinjiang, and the temperature in some areas will even reach an astonishing 45 degrees!
Why is there such a hot weather in the forecast? In fact, it is all related to abnormal changes in atmospheric circulation. Recently, there have been some unusual fluctuations in the westerly wind belt over the continent, which have led to the intensification of hot and dry air masses and the intensification of cold vortex thunderstorm activity.
Second, the large-scale high temperature in North China Huanghuai is determined!
According to the supercomputer forecast, the trend of excessive amplitude of the westerly wind belt will continue, resulting in more than one continental warm high pressure ridge in sunny and hot weather in the future, which will continue to move eastward from Central Asia to Xinjiang, causing waves of new high temperatures in the north.
Especially around May 16, the westerly wind belt over the mainland will form a strong uplift of the high-altitude warm ridge in the northwest region, and even the combination of the strong continental high and the subtropical high will penetrate into the mainland Xinjiang, so that the strength of the dry and hot air mass in the northwest region will be rapidly strengthened, and the recent dry and hot high temperature will be further escalated, and the local temperature in Turpan, Xinjiang will even reach 45 degrees in the afternoon of May 16!
At present, the first wave of warming was formed in the eastern part of Northwest China-North China-Huanghuai on May 13-14, and after the Turpan Basin may have a strong high temperature of 45 degrees on May 16, another wave of warming from west to east in the north was set off. For example, it can be seen in the current forecast that the temperature in Xi'an, Shaanxi Province will continue to rise next week, especially around May 17, and there will be a high temperature of more than 35 degrees. The Central Meteorological Observatory also pointed out that after May 17, there will be high temperatures of more than 35 degrees in some areas of Huanghuai and North China.
3. Dry the hot air
The dry hot air mass is a kind of atmospheric air mass with low humidity, high temperature and high stability, which is mainly distributed in the Tarim Basin and Qaidam Basin in the northwest of the mainland, and is one of the main sources of high temperature in late spring and early summer in the northern part of the mainland. The characteristics of the dry hot air mass are that its water vapor content is very low, so the air is very dry, and its temperature is very high, so the sunlight is very hot, its stability is very high, so there are few clouds, these factors make the dry hot air mass have a strong heating ability, which can make the ground temperature rise rapidly and form a high temperature weather. When the hot and dry air mass is controlled by the warm ridge at high altitude or the northwest airflow in front of the ridge, it will move eastward, affecting North China, Huanghuai and other regions in the north of the mainland, resulting in a sunny and hot weather state without rain.
Moreover, because the water vapor content of the hot and dry air mass is very low, its humidity is low, which leads to the emergence of a disastrous weather called "hot and dry air". Hot and dry wind is a disastrous weather that affects the growth and development of crops due to high temperature, low humidity and certain wind conditions, resulting in reduced yield. Hot and dry wind, also known as "dry wind" and "hot dry wind", commonly known as "fire south wind" or "fire wind", is one of the agricultural meteorological disasters. A dry, hot wind that occurs in the warm season, causing damage to wheat grains during the milk ripening stage. When the hot and dry wind appears, the temperature increases significantly, the humidity decreases significantly, and there is a certain wind, the transpiration intensifies, and the root system cannot absorb water, which often leads to insufficient grain filling of wheat, serious grain and even wilting and death. It occurs in the late spring and early summer of North China, Northwest China, and the Huanghuai region of the mainland. Generally, it is divided into two types: high temperature and low humidity and heat and dry after rain, both of which are mainly high temperature hazards.
At present, the forecast of the Central Meteorological Observatory also points out that on May 14 and May 17-20, there will be 3-5 days of dry and hot wind weather in most of Huanghuai and southern North China. In this way, the trend of greater high temperatures in the north has become more and more certain, and it will also bring hot and dry winds to the weather, which is undoubtedly a huge threat to the wheat producing areas in the north of the mainland.