Typhoon 'Chantu' Makes Landfall West of Jeju on the 17th... 500mm Deluge in Jeju from the 12th to 15th

Indirect Typhoon Impact: Heavy Rain in Jeju and Southern Coast Areas on 15-16
Northwest High Pressure Influence, Typhoon Stays in Shanghai for 3 Days
Dry Air Meets Moisture, Causing Significant Development of Rain Clouds
"It Is Unusual for a Very Strong Typhoon to Stall and Move Eastward"

[Asia Economy Reporter Han Jinju] Typhoon Chanthu, the 14th typhoon, is moving eastward from near Shanghai, China toward South Korea, and is expected to bring heavy rain to Jeju and the southern regions around the 15th and 16th.

On the 12th, the Korea Meteorological Administration (KMA) held an emergency briefing regarding Typhoon Chanthu and precipitation forecasts, predicting that from the 15th to 16th, indirect effects of the typhoon will cause heavy rainfall centered on Jeju, and around the 16th, as the typhoon comes under direct influence, heavy rain will fall on Jeju and the southern regions.

From the night of the 12th through the 15th, Jeju is expected to receive more than 500mm of rainfall, with about 100 to 300mm of heavy rain. From the 14th, the southern coast of Gyeongnam, western Gyeongnam, and the Jeonnam area will see about 20 to 80mm of rain. Rainfall on Jeju will increase sharply from the 14th, and the amount of rain along the southern coast is expected to increase from the 15th.

Han Sang-eun, a meteorological expert at the KMA, analyzed, "Typhoon Chanthu will remain stationary for about three days and then start moving around the 15th to 16th. A strong precipitation cloud band will develop near Jeju, where moist air from the south meets cool, dry air from the north, explosively developing clouds and causing heavy rain on Jeju between the 14th and 15th."

According to the KMA's medium-term forecast, rain is expected across most regions nationwide from the night of the 16th through the afternoon of the 17th. There is also a forecast for rain nationwide on the afternoon of the 21st, during the Chuseok holiday. However, since the typhoon is stationary before moving, weather variability is high.

As of 9 a.m. on the 12th, Typhoon Chanthu has a central pressure of 935 hPa, maximum sustained winds of 50 m/s, and a strong wind radius of 280 km, making it a very strong typhoon. It is expected to move north of Taiwan's sea on the night of the 12th, remain near Shanghai from the 13th to 15th, and then advance west of Jeju around 9 a.m. on the 17th. The KMA explains that the typhoon's intensity weakens somewhat while stationary near Shanghai but redevelops as it moves eastward from the 16th under the influence of an upper-level trough.

The expert said, "There has never been a case of a typhoon with such strong intensity moving northward like this, nor a typhoon with a similar track, making this an extremely unusual case. The approach of an upper-level trough from the west causes the typhoon to remain stationary before moving eastward, resulting in very high variability."

This typhoon is greatly influenced by the strength and extent of high pressure. If the typhoon weakens rapidly, the stationary period in the west will lengthen, and the stronger the upper-level trough descending from the northwest via the northern jet stream, the earlier the typhoon may affect South Korea.

A similar case was Typhoon Doug, the 13th typhoon in 1994, which remained stationary near Jeju for about four days, dumping 300 to 400mm of heavy rain on Jeju and the southern coast. In that case, high pressure formed northwest of the typhoon, weakening its northward track. However, this typhoon differs in that it remains stationary due to the approach of an upper-level trough from the west before moving eastward.

The expert explained, "Based on the current forecasted track, the typhoon is expected to move near Jeju or the southern coast, with southerly winds continuously supplying moisture and dry air positioned over South Korea, causing heavy rain on Jeju even though it is not under the direct influence of the typhoon. The central regions are relatively far from the influence zone, so rainfall amounts there are expected to be comparatively low."

This content was produced with the assistance of AI translation services.