Super Typhoon Lan as seen by the T-PARCII G-II research aircraft on Saturday afternoon, 21 October 2017. Image credit: Kosuke Ito and the Tropical cyclones-Pacific Asian Research Campaign for Improvement of Intensity estimations/forecasts (T-PARCII) program. Photo: Kosuke Ito

Dr. Jeff Masters
22 October 2017
(Wunderground) – Typhoon Lan made landfall near Omaezaki City, Japan, about 120 miles southwest of Tokyoa, near 3 am JST Monday. At landfall, Lan was a Category 2 storm with sustained 1-minute winds of 105 mph. Lan drenched Japan’s main island of Honshu with dangerous torrential rains on Sunday as the Category 3 typhoon, with sustained winds of 120 mph at 8 am EDT Sunday, sped northeast at 29 mph towards Tokyo. Lan was interacting with a frontal system that has brought high wind shear and dry air into the typhoon, resulting in the collapse of its inner core. Passage over cool waters of 25°C (77°F) as Lan approached the coast caused further weakening to a Category 2 typhoon at landfall.While high winds will cause considerable damage and loss of power across much of Honshu, Lan’s primary threat is heavy rain. A moist flow of tropical air interacting with a stalled front had already begun to trigger heavy rains over Japan on Friday, and now that Lan’s rains have reached the nation (see latest Japanese radar images), record 48-hour rainfall amounts have been observed in some locations. As of 21:20 JST Sunday, Lan brought a record 48-hour rainfall amount for October of 700 mm (27.56”) to Shingu, located about 300 miles southwest of Tokyo. In records going back to 1976, the highest 48-hour rainfall there for any month was 782 mm (30.79”). Kamoda, in the Shikoku region, also set an October 48-hour rainfall record today, with 299.5 mm (11.79”.) Additional heavy rains of over 10” are expected over some areas of Japan. [more]

Category 3 Typhoon Lan Batters Japan