A residential area is covered with snow in Ilsan, Gyeonggi Province where a snow advisory is issue for Thursday morning, Jan, 26. Yonhap

A heavy snow advisory was issued Thursday in the greater Seoul area and some central parts of the country, the state weather agency said.

The advisory went into effect in Seoul's southwest and northwest regions, Incheon, parts of Gyeonggi Province surrounding Seoul and the coastal region of South Chungcheong Province, according to the Korea Meteorological Administration (KMA).

The advisory is given when the snowfall is expected to reach 5 centimeters or more within 24 hours.

The snowfall was heaviest overnight and into early Thursday, impacting the morning commute, the KMA said.

The KMA advised citizens to use public transportation and leave for work earlier than usual to avoid heavy traffic congestion.