The worst yellow dust storms this year are forecast to blanket South Korea on Sunday as winds continue to bring a thick layer of dust from the desert areas in northeastern China. The Korean weather agency posted a yellow dust advisory for five northwestern islands and issued another warning for central and southwestern provinces four hours later. The dust warnings are likely to be expanded nationwide later in the afternoon as winds will bring more dust clouds to the peninsula, the Korea Meteorological Administration (KMA) said, according to South Korea\'\'s news agency (Yonhap). The agency said that the level of dust particles in the air is expected to exceed 800 micrograms per cubic meter in some regions, prompting it to issue the highest-level warning. \"This yellow dust forecast to hit the country until tomorrow will be the worst this year and is highly likely to lead to the issuances of the highest-level warning,\" a KMA official said. The KMA issues the highest warning when the dust level in the air reaches and remains over 800 micrograms for an hour.