SEOUL-- Typhoon Hinnamnor is forecast to reach waters off Jeju Island this week as a "very strong" typhoon, causing heavy rains across South Korea and strong winds in lower parts of the country, the state weather agency said Sunday.

According to the Korea Meteorological Administration (KMA), the typhoon, the 11th this year, is expected to arrive 480 kilometers northeast of Taiwan's Taipei as a "super strong" typhoon at 3 a.m. Monday before losing steam to reach 340 km south-southwest of the southern island of Jeju's Seogwipo around 3 p.m. as a "very strong" typhoon.

Typhoons are classified into four categories, from medium to strong, very strong and super strong.

Super strong refers to typhoons with a maximum wind speed of at least 54 meters per second.

After brushing past Jeju, Typhoon Hinnamnor is forecast to make landfall 20 km north-northwest of the southern port city of Busan by 9 a.m. Tuesday, with an atmospheric pressure of 950 hectopascals at its center and a maximum wind speed of 43 meters per second, according to the KMA.

The typhoon's strength when it reaches Busan is forecast to weaken to "strong" although it is expected to become the strongest typhoon ever to make landfall in South Korea.

President Yoon Suk-yeol held a meeting in the crisis management center of the presidential office to check the government's response system.

"Natural disasters cause even greater damage and pain to the socially weak," he said at the meeting with his senior aides, also noting that Chuseok is just around the corner, according to his spokesperson Kang In-sun. The four-day Chuseok fall harvest holiday season begins on Friday.

"We must put the people's safety first and do our best to minimize damage from the typhoon," he was quoted as adding.

Yoon instructed Prime Minister Han Duck-soo and other Cabinet members, who joined the meeting virtually, to come up with preemptive measures against the typhoon, Kang said.

According to the Central Disaster and Safety Countermeasures Headquarters, preliminary weather advisories were issued in the southern cities of Gwangju, Busan, Daegu and Ulsan and in the surrounding provinces of South and North Jeolla and South Gyeongsang at 5 a.m. Sunday.

The Central Disaster and Safety Countermeasures Headquarters' emergency response posture was upgraded to the highest Level 3 as of 4:30 p.m. for the first time in five years in terms of tyhpoon response.

The government also recommended schools skip classes or switch to online learning and private firms move work hours on Tuesday morning when Hinnamnor is expected to make landfall.

The warnings came a day after an advisory was issued over Jeju.

Parts of the country received rain on Sunday as a result of the approaching typhoon, which was traveling northward from waters 390 km northeast of Taipei, Taiwan as of 4 p.m. Sunday.

The accumulated precipitation in parts of Jeju from Friday through Sunday afternoon surpassed 300 millimeters.

The country is expected to receive between 100 and 300 millimeters of rain between Sunday and Tuesday, with the mountainous areas of Jeju receiving more than 600 millimeters, the KMA said.

On Tuesday, the country could receive between 50 and 100 millimeters of rain per hour, a level similar to that seen during record rainfall in early August.

The typhoon could also bring record strong winds, with the KMA forecasting maximum speeds of 40 to 60 meters per second in Jeju and other lower coastal areas between Monday night and Tuesday.

The current record is 63.7 meters per second measured in the eastern coastal city of Sokcho on Oct. 23, 2006.

No casualties or property damage have been reported from the effects of Typhoon Hinnamnor so far.

More than 600 trails in national parks across the country were closed starting 5 p.m. Sunday. Operations of 52 ferries serving 37 routes have already been suspended, while the governments of Jeju, South Jeolla Province and other nearby municipalities have ordered some 33,000 vessels to move to safety.

A total of 198 people from 146 households in vulnerable areas of Busan were being evacuated due to safety concerns as of Sunday evening while 12 flights were canceled, including those to Jeju.

At Yoon's orders, the government on Saturday raised the typhoon alert level by one notch to "yellow" from "blue."

Source: Yonhap News Agency