| Above: Typhoon Jongdari as seen on MODIS imagery on Saturday afternoon (JST) July 28, 2018. Image credit: NASA. |
Talk about weather whiplash: after suffering extreme flooding that killed 225 people during the first week of July, Japan endured a scorching mid-July heat wave that brought the country its hottest temperature ever recorded on July 23: 41.1°C (106°F) at Kumagaya, 40 miles (65 km) northwest of Tokyo. Now, the pendulum has swung again to flood, as Typhoon Jongdari drenches Japan. Jongdari made landfall near 1 am JST (UTC+9) Sunday (noon EDT Saturday) in Japan’s Mie Prefecture as a Category 1 storm with top sustained winds of 80 mph. Radar imagery from the Japan Meteorological Agency showed Jongdari was dumping rains in excess of 80 mm per hour (3.15” per hour) at landfall, which is sure to cause flooding problems. The core of this heavy rain area passed over Soni, which recorded 168 mm (6.61”) of rain in three hours, beginning at midnight JST on Sunday.
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| Figure 1. Radar imagery from the Japan Meteorological Agency showed Jongdari was dumping rains in excess of 80 mm per hour (3.15” per hour) at landfall. |
Forecast for Jongdari: potentially dangerous rains for Kyushu
Jongdari is being steered to the west by a strong ridge of high pressure to its north and a low to its south, and will steadily weaken as it interacts with land, and wind shear increases. By Monday, the storm will be moving on more of a west-southwesterly track over southern Japan, and the Joint Typhoon Warning Center predicted in their 11 am EDT Saturday advisory that Jongdari would weaken to a remnant low on Monday. However, the 6Z and 12Z Saturday runs of the HWRF model predicted that Jongdari would survive the traverse of Japan, and emerge over the 28°C (82°F) waters south of the southernmost main Japanese Island of Kyushu on Monday. The warm waters there would allow the storm to regenerate into a Category 1 typhoon that would move only very slowly, dumping dangerously high rainfall amounts in excess of two feet over Kyushu. Hopefully, this forecast is incorrect, and the 12Z run of the European model will be more accurate: that model showed Jongdari remaining a weak tropical storm and moving steadily away from Japan on Monday and Tuesday, resulting in much less rainfall for Kyushu.
Summary of the July 14 – July 28 heat wave in Japan and Korea
An extreme and unusually persistent kink in the jet stream brought a very strong ridge of high pressure to east Asia beginning around July 14, when all-time heat records started falling. The heat wave is being blamed for at least 86 heat-related deaths in Japan since May, with more than 30,000 undergoing heat-related hospitalizations. The heat wave is being blamed for at least 10 deaths in Korea. Dozens of stations in Japan set their all-time heat records during the event. Just one sample of how extreme this heat wave was: beginning on July 14, Kyoto, Japan (where weather records extend back to 1881) beat its previous all-time high for July (38.3°C/101.0°F from July 26, 2014) on six out of seven days, culminating on July 19 with a high of 39.8°C (103.6°F), a tie for its all-time high temperature for any month (previously set on August 8, 1994):
38.5°C (101.3°F) on Saturday, July 14
38.7°C (101.7°F) on Sunday, July 15
38.5°C (101.3°F) on Monday, July 16
39.1°C (102.4°F) on Wednesday, July 18
39.8°C (103.6°F) on Thursday, July 19
38.6°C (101.5°F) on Friday, July 20
The heat wave also brought the Korean Peninsula record heat. Over the past week, a number of stations in North and South Korea with a period of record (POR) over 40 years set their all-time heat records (thanks go to Maximilliano Herrera and Etienne Kapikian for researching these records):
39.9°C (103.8°F) Uiseong, South Korea, July 27: second highest temperature reliably measured in the nation (the only higher temperature: 40.0°C at Daegu in 1942).
39.9°C (103.8°F) Hayang, South Korea, July 23: second highest temperature reliably measured in the nation (tied with the July 27 reading at Uiseong).
39.7°C (103.5°F) Wonsan, North Korea, July 22 (1.7°C above its previous all-time record in July 1977)
39.5°C (103.1°F) Hapcheon, South Korea, July 26
38.2 C (100.8°F) Chunggang, North Korea, July 28
37.5°C (99.5°F) Suwon, South Korea, July 22
36.6°C (97.9°F) Boeun, South Korea, July 21
32.9°C (91.2°F) Taegwalliong, South Korea (842m elevation), July 22
