I really can't understand the winter of 20 15.
Meteorologist: Strong cold air moves south to form a supercell storm.
According to the data released by Guang 'an Meteorological Bureau, the maximum temperature in Guang 'an dropped above 15℃ from 20: 00 on the 4th to 20: 00 on the 5th, with moderate to heavy rain and local heavy rain. The maximum precipitation occurred in Dalong Township, Guang 'an District, which was104.8 mm; ; The rainfall at 35 stations in Guang 'an (*** 18 1 station in the whole city) exceeds 50 mm, and the heavy rainfall is mainly concentrated in Yuechi County, Guang 'an District and Vu Thang, and the spring drought in most places has been alleviated.
Thunderstorms are accompanied by strong winds, hail and other bad weather, and the wind force in some places is above 10. The instantaneous maximum wind speed of Vu Thang drummer 2 1: 33 is 28.3m/s (10), Sanxi 2 1: 4 1: 00 is 38.5m/s (13), and Longfei 2/kloc.
What caused this extreme weather? Wang Xiaofang, a senior engineer of Guang 'an Meteorological Bureau, said that this kind of extreme weather is rare, especially in Sanxi and Drummer in Vu Thang, where there is a strong wind of 13, which is very rare on land. There are three main reasons for its formation.
The first reason is that the temperature is obviously high and the gas layer is extremely unstable.
Since late March, due to the northerly airflow, the weather in Guang 'an has been sunny and hot with little rain. In April 1 day, the daily maximum temperature in most areas of Guang 'an exceeded 34℃, and the highest temperature in Vu Thang reached 34.3℃, which was abnormally high.
Under the continuous influence of high temperature, the gas layer is extremely unstable and has the basic conditions of strong convection such as strong wind and hail.
Reason 2: Strong cold air moves south, leading to extreme weather.
The cold air in the north began to affect Guang 'an from north to south at 9: 00 pm on the 4th, which provided favorable trigger conditions for the release of unstable energy. Guang 'an formed the strongest cold and warm air confrontation area, which was blocked by southwest warm current, resulting in a large-scale strong convective weather process in Guang 'an, and thunderstorms and windy weather generally appeared.
The third reason: the terrain is limited, forming a supercell storm.
The blocking of the cold air by the topography of Huaying Mountain also led to the further increase of the converging airflow at the bottom. Vu Thang and Yuechi County are located in the northwest of Huaying Mountain, which is also an important factor of local strong convection.
At about 2 1 hour on April 4th, a small-scale strong convective supercell storm developed in a short time due to the large topographic relief in the west of Vu Thang Drum Machine and uneven local thermal distribution. After that, it gradually expanded eastward, and developed most vigorously in the areas of Longfei Sanxi, Vu Thang and Qiaojia in Yuechi County. When the supercell storm crosses the border, the wind direction changes suddenly, and the wind force increases sharply, accompanied by severe thunderstorm, hail and other disastrous weather.
Wang Xiaofang introduced that in meteorology, it is generally divided into 12 grades according to the magnitude of wind power, but in nature, the wind power sometimes exceeds 12. There was a strong wind of 13 in Vu Thang this time. "Its destructive power and frequency of occurrence are very rare on land.