The winds pushed rapidly southward on Saturday, bringing gusts between 24.5 and 28.4 m/s to Hubei and Zhejiang provinces, as well as Shanghai. Meanwhile, sand and dust storms swept across the provinces of Yunnan and Guizhou and the Guangxi Zhuang autonomous region, sending PM10 particle levels to dangerously high levels.

Xin Xin, a senior analyst at Weather China, said the extreme winds were the result of a clash between strong cold air and warm, humid airflow, combined with a high-altitude cold high pressure system.

"During winter and spring, such a collision can quickly trigger a counterclockwise rotation, giving rise to a temperate cyclone," Xin said. "It's like a spinning weather gyroscope. When reinforced by other atmospheric conditions, it spins faster, as if repeatedly struck by an invisible whip."

Xin added that such systems can rapidly intensify in a short time, creating gale-force winds comparable in strength to a typhoon.

The National Meteorological Center said the winds would begin to subside in the south starting on Sunday. But many areas in the north — including Inner Mongolia, Hebei and Beijing — are expected to remain under the influence of winds up to 30.5 m/s.

At 6 am on Sunday, the national observatory issued an orange alert for strong winds across wide swaths of northern China, effective through 8 am on Tuesday.