BEIJING - China's top meteorological authority on Friday issued an orange alert as Typhoon Fitow is set to hit the country's southeast coastlines late Sunday.

Fitow, the 23rd of the year, strengthened to a strong typhoon on Friday afternoon. At 5 p.m. its center on the northwestern Pacific Ocean was about 850 kilometers east of Taipei, packing winds of 42 meters per second, according to the National Meteorological Center (NMC).

The center forecasts Fitow to reach East China Sea on Saturday and make landfall in the provinces of Zhejiang and Fujian on Sunday, bringing strong wind.

China has a four-tier color-coded weather warning system, with red representing the most severe weather, followed by orange, yellow and blue.