Wipha, the 13th tropical storm this year on heels of Nari, was approaching China, Xinhua quoted sources with the provincial meteorological observatory of Zhejiang as saying on Sunday. Formed at 8 a.m. Sunday on the sea of northeast Philippines, the tropical storm was located at 20.6 degrees north and 130.7 degrees east at 2 p.m., about 1,360 kilometers away from east China's Zhejiang Province, according to the observatory. Wipha, packing winds of 83 kilometers per hour at its eye, is heading northwestwards at a speed of 20 kilometers per hour and gaining momentum. It is forecasted to enter the East China Sea on Monday night or Tuesday morning and unleash gales. The meteorological observatory warned local people to be alert of the storm.