Seasons and Genesis of Quasi-static Front in Kunming

The seasons and causes of quasi-static front in Kunming are as follows:

The quasi-static front in Kunming mainly appears from June 1 1 to April of the following year, and often lasts for 10 ~ 15 days.

Except in July, the areas with the highest frequency of quasi-static front activity in Kunming are located in southwest Sichuan, northeast Yunnan and southwest Guizhou.

The quasi-static front in Kunming is not "static", it often swings around a certain position, and it also retreats to the north during the day and advances to the south at night, which is more obvious when the static front is weak.

It is mainly formed by metamorphic polar continental air mass and southwest airflow blocked by Yunnan-Guizhou Plateau topography. Clouds are low and thin, and it is easy to form continuous rainy weather.

Influence of quasi-static front in Kunming on weather and climate in southwest China;

Most of Yunnan, located in the southwest of the front, is controlled by a single heating flow. The sky is blue and Wan Li, the sun is shining and the temperature is high. For example, the average temperature in Kunming is 7.7℃ in 65438+ 10, and there is no severe cold in winter.

The northeast of Liangshan Prefecture in Sichuan, the northeast of Yunnan and most parts of Guizhou are located on the cold air side, with northerly winds and low temperatures. For example, in June 5438+10/October, the average temperature in Guiyang was 5.0℃, and it rained continuously; The number of days of precipitation ≥ 0. 1mm per month is more than/kloc-0 ~15 days, so it is said that there are no three sunny days.

When the cold air is strong and the front is located to the west of Kunming, the eastern part of Yunnan is below the static front, the temperature drops suddenly, and the weather turns cloudy or there is light rain. Therefore, there is also a saying in Yunnan that "there is no cold and heat in the four seasons, and it will become autumn when it rains".

This front is the northern boundary of the dry and warm continental air mass that controls Yunnan, and it is also the northern boundary of the monsoon climate in Yunnan. During this period, northeastern Yunnan and most parts of Guizhou were controlled by cold air moving at mid-latitude. Now take Kunming and Guiyang as representatives to illustrate their differences.