Typhoon Champi, the 30th storm of the season, has shifted its projected path toward Japan's Kyushu region, but strong rain and wind are forecast for Jeju Special Self-Governing Province and southern Korea throughout the weekend.
As of 3 a.m. on the 23rd, Champi was moving northwest at 18 kilometers per hour over waters about 460 kilometers southeast of Taipei, Taiwan, the Korea Meteorological Administration said. Its central pressure was 950 hectopascals, with maximum sustained winds near the center of 43 meters per second, or 155 kilometers per hour, placing it at category 3 intensity.
Champi had intensified to a central pressure of 910 hectopascals and maximum winds of 56 meters per second on the 21st, but weakened as it approached Taiwan. The weather agency expects the storm to turn northeast near Taiwan and weaken to category 1 intensity, with winds of 24 meters per second, by 3 a.m. on the 25th. It is then forecast to become an extratropical cyclone by 3 a.m. on the 26th, over land about 60 kilometers north of Kagoshima, Japan. That transition is now expected earlier than in the previous day's forecast.
The projected track has shifted over three days. In a forecast issued on the morning of the 21st, the Japan Meteorological Agency had Champi approaching Jeju before heading toward the waters near Tsushima. The agency revised the track toward Japan starting the 22nd, and in an afternoon update that day shifted it further south, projecting a path straight through Kyushu.
The agency maintained the Kyushu track in its forecast on the morning of the 23rd, converging with projections from the Korea Meteorological Administration and the U.S. Joint Typhoon Warning Center, both of which had anticipated a Kyushu landfall. According to the Japan Meteorological Agency, as of 6 a.m. on the 23rd, Champi was moving northwest at 15 kilometers per hour south of Okinawa, with a central pressure of 955 hectopascals, maximum sustained winds of 40 meters per second and peak gusts of 60 meters per second.
Landfall May Be Avoided, but Jeju's Mountains Face More Than 150 Millimeters of Rain and Southern Seas Waves Up to 5 Meters
Even with the track leaning toward Japan, the Korean Peninsula is expected to feel indirect effects. The Jeju Regional Office of Meteorology forecast that rain would begin between noon and 3 p.m. on the 23rd, bringing 50 to 100 millimeters to Jeju through the 25th, with more than 150 millimeters possible in mountainous areas and mid-mountain zones.
Rain will continue in some areas until early on the 26th. Jeju will see gusts of 55 kilometers per hour or more starting the afternoon of the 23rd, reaching 70 kilometers per hour or more in mountainous areas, while the southern coast will see winds of around 15 meters per second from early on the 24th. Waves off Jeju are projected to rise to between 2 and 5 meters on the 25th.
The rain will expand to the southern coasts of Jeollanam-do and Gyeongsangnam-do on the night of the 23rd. It is expected to end across most of the Jeolla region by the afternoon of the 25th, and across the Gyeongsang region and southern coast after the evening of the 25th. Expected rainfall through the 25th is 20 to 60 millimeters in Busan, Ulsan and South Gyeongsang Province as well as Gwangju and Jeonnam, 5 to 40 millimeters in Daegu, North Gyeongsang Province, Ulleungdo and Dokdo, 5 to 20 millimeters in Jeonbuk State and 5 to 10 millimeters in the Chungcheong region.
The typhoon is weakening because sea surface temperatures around Korea are low and strong westerly winds in the upper atmosphere are blocking its northward movement. Even as it weakens, however, moisture from the south continues to flow in, sustaining the rain. If the storm moves slowly near Taiwan, that moisture will linger longer; if it accelerates northeast, the rain could end sooner.
Should Champi trigger typhoon advisories over parts of the southern seas on the 25th and be classified as a storm affecting Korea, it would become the latest-season typhoon to do so since 1951. The current record is held by Typhoon Zeb, which affected the country from Oct. 16 to 18, 1998 — a mark that would be broken after 28 years. The weather agency said the areas of rainfall and the scope of maritime advisories could change depending on the storm's track and speed, and urged the public to check the latest forecasts.