Jeju Island’s weather agency issued a heavy rain watch at 9 a.m. Friday for the eastern parts of the island. 

The Korea Meteorological Administration’s office in Jeju also raised its heavy rain alert issued for the island’s southern parts to a heavy rain warning. The same advisory is also in place for Jeju’s mountainous areas.  

The weather agency forecast that Jeju’s eastern and southern parts will see 30 millimeters of heavy rain per hour, accompanied by thunder and lightning.  

The island is expected to witness between 50 and 100 millimeters of precipitation from Friday to 3 a.m. Saturday. Mountainous areas and southern parts are likely to see more than 200 millimeters of rain.  

The agency also issued a strong wind watch for Jeju’s mountainous areas as well as eastern and southern parts.  

A wind shear advisory is currently in place for Jeju International Airport and Mount Halla's seven hiking trails have been closed due to inclement weather.