Tropical Depression Jongdari moved toward South Korea on Tuesday, threatening to buffet the country with heavy rain and strong winds.
The approaching storm, considered a typhoon in South Korea, canceled some flights and set off coastal flood warnings on Jeju Island, a popular holiday destination in the south. They issued evacuation orders for the island’s piers, ports and beaches and closed all hiking trails.
Jongdari had maximum sustained winds of 40 miles per hour on Tuesday, the U.S. Navy’s Joint Typhoon Warning Center said. The storm was forecast to pass Jeju on Tuesday evening, skirt South Korea’s west coast overnight and make landfall on near Seoul, the capital, on Wednesday morning.
Forecasters said Jongdari was expected to dump as much as four inches of rain on some parts of Jeju, and one to three inches on some areas of mainland South Korea.
The Korea Meteorological Administration, which labels tropical cyclones with wind speeds greater than 38 m.p.h. as typhoons, issued typhoon warnings on Jeju Island and the southwestern coast of South Korea.
More than 30 flights that had been scheduled to depart from or arrive at Jeju International Airport on Tuesday afternoon were delayed, according to the airport’s website. Korean Air said that it had canceled six flights to and from Gimhae International Airport in the southern city of Busan on Tuesday and Wednesday. A sudden wind change warning was active at the Jeju airport until Tuesday night.
Korea Post, the national postal service, said mail deliveries could be delayed in areas affected by the storm because of disruptions to flights and ships.
Jongdari formed early Monday in the Pacific Ocean near Okinawa, a southern Japanese island. Meteorologists said the storm would bring hot moisture from the south, extending the heat wave that has sustained 90-degree daytime temperatures in South Korea for several weeks.
