Geographical reasons for "three days without sunshine" in Guiyang

Guizhou is affected by the quasi-static front stop of Kunming, and the Yunnan-Guizhou Plateau is common, with long rainfall duration and continuous rainfall. So there is a saying that there is no sunny day in winter in Guizhou.

When the cold and warm air masses are equal in strength, fronts that rarely move or move slowly are called quasi-static fronts.

In fact, there is no absolute stillness. During this period, the cold and warm air masses are also fighting each other. Sometimes the cold air mass dominates, and sometimes the warm air mass dominates, making the front swing back and forth.

Quasi-static is a very important knowledge point in middle school geography curriculum. The cold and warm air masses on both sides of the front are evenly matched, or the movement range is very small when blocked by terrain. We call this front a quasi-static front. In meteorological forecast, it is generally believed that the position of the front does not change much within 6 hours on the weather map, which is the basis for judging the quasi-static front.

Kunming quasi-static front

Also known as Yunnan-Guizhou quasi-static front. Located in Yunnan-Guizhou Plateau, 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. The "three sunny days" in Guizhou Plateau are related to the quasi-static pre-stop activities in Kunming. Most of them appear in winter, and the number of days during this period accounts for about 1/2 of the whole year. The front area is mostly located between Guiyang and Kunming, with a slightly northwest-southeast trend.