The sixth and seventh tropical storms of the year, "Lionrock" and "Kompasu," will bring gusty winds and torrential rains to east China's Fujian and Zhejiang provinces from Tuesday to Friday.

All ships and fishing boats in the sea off Fujian and Zhejiang have been advised to take shelter from the storms.

"Kompasu," which means compass in Japanese, formed on Sunday evening in the East China Sea and was moving northwest at a speed of 15 kilometers per hour, said Zhejiang meteorological station in a statement on Monday.

"Kompasu," together with "Lionrock" and the eighth tropical low pressure system, will bring downpours to the coastal region of Zhejiang on Tuesday and Wednesday with wind speeds of up to 32.6 meters per second.

Torrential rains are forecast to hit both costal and inland areas of Fujian with rainfall of more than 300mm in some coastal regions from Tuesday to Friday.

But the Fujian provincial meteorological station said the two tropical storms and one tropical low pressure system may interact, causing an unpredictable outcome.

Meanwhile, the northern downdraft of "Lionrock" and the south-west monsoon has caused an extreme heat wave in the east part of southwest China's Guangxi Zhuang Autonomous Region with maximum temperatures reaching 36 degrees Celsius.