HAIKOU, Sept. 18 (Xinhua) -- South China's coastal provinces of Hainan and Guangdong on Thursday moved in lockstep to activate their Level-IV typhoon emergency response measures, as the year's 17th typhoon approached. It is forecast to make landfall along the Guangdong coast between Huilai County and Taishan City from noon to night on Friday, likely as either a tropical storm or a severe tropical storm -- bringing torrential rains to Guangdong on Friday and Saturday before weakening and continuing northwestward. The Guangdong flood control headquarters has ordered all local authorities to closely monitor the typhoon and implement emergency response measures to ensure public safety and safeguard property. In Hainan, the typhoon emergency response applies only to marine operations -- as strong gales are forecast from Thursday afternoon through Friday. China has a four-tier emergency response system, with Level I representing the highest severity.