Causes of extreme weather in the central plains of North America

The central plain is low and flat, with no east-west mountains, and the north and south are open, which makes the north-south airflow unimpeded. In winter, the polar cold air mass can go south and suddenly cool down. In summer, the tropical heating mass from the Gulf of Mexico can go north freely, and the weather is sultry and rainy. Under the control of cold and warm air masses, a temperate continental climate has formed in the Central Plains, with strong seasonal changes in temperature and precipitation and strong continental nature.