Former Super Typhoon Noul Becomes Post-Tropical, But Still Blasts Tokyo With High Winds

Nick Wiltgen
Published: May 12,2015



 
Former Super Typhoon Noul was declared post-tropical by the Japan Meteorological Agency Tuesday evening after bringing record-breaking winds and heavy rainfall to Japan's southern islands earlier in the day. Despite the transition to a non-tropical low-pressure system, the remnants of Noul have continued to bring strong winds and heavy rain to some of Japan's most heavily populated areas.
Tokyo's Haneda Airport, on the shores of Tokyo Bay, clocked a 61-mph sustained wind with a gust to 76 mph at 10:46 p.m. Tuesday local time (9:46 a.m. Tuesday U.S. Eastern time). Nearby Yokohama gusted to 61 mph, while the Edogawa Waterfront observation site near the eastern edge of Tokyo gusted to 77 mph. Winds were much lighter inland; Tokyo's main observation site near the Imperial Palace only gusted to 43 mph.
Rainfall amounts of 2 to 4 inches (50 to 100 mm) were common across the Tokyo area. Farther west, up to 6 inches fell in parts of Shizuoka and Kōchi prefectures, along the Pacific coast.
Noul originated in the tropical Western Pacific, brushing the island of Yap before strengthening rapidly and clipping the northern Philippines as a super typhoon over the weekend.
(MORE: Impacts From Noul | Noul Strikes Yap, then Philippines)
At 6 p.m. Tuesday Japanese time (5 a.m. Tuesday U.S. Eastern time), the Japan Meteorological Agency declared Noul a non-tropical low-pressure system. The center of the low was south of Shikoku, one of Japan's four main islands. It continues to race to the northeast and was moving across the Tokyo area early Wednesday local time.
Earlier, Noul passed directly over Amami Oshima, an island about 200 miles south of the southwestern tip of mainland Japan and about 120 miles northeast of Okinawa. The Amami Airport on that island observed a 69-mph (111-kph) sustained wind at 10:39 a.m. Japanese time; the peak gust there was 90 mph (144 kph) around the same time.
Noul was much stronger when it arrived in Japan's southernmost islands late Monday night (Japanese time). The island of Shimoji clocked a sustained wind of 102 mph (165 mph) just after 1 a.m. Tuesday (local time) while an intense rainband on the back side of Noul moved through. The peak gust was 131 mph (211 kph), setting a national record for Japan's highest wind gust ever recorded in the month of May, excluding the summit of Mount Fuji.
Noul, which looked unimpressive on satellite but showed a well-defined eye on Japanese radar early Tuesday, made several slight wobbles to the left after passing through the Yaeyama island chain late Monday evening. These wobbles took the center just west of Okinawa rather than directly overhead. A heavy rain band swept through Okinawa around daybreak Tuesday, but quickly moved out, dropping only about half an inch (10 to 15 mm) of rain.
Winds gusted to nearly 50 mph (80 kph) on Okinawa around sunrise Tuesday. Webcams showed traffic moving smoothly on the island, which is well prepared for typhoons and their powerful winds. The U.S. military's Kadena Air Base on Okinawa has declared "All Clear" as winds subsided quickly after Noul's passage.
(INTERACTIVE: Satellite Image of Noul)

Infrared Satellite Image

As Noul passed through the Japan's Yaeyama island chain just east of Taiwan, the main observation site on Ishigaki Island (Ishigaki-jima) recorded a sustained wind of 64 mph (104 kph) just before midnight Monday evening. That set the location's an all-time record for strongest sustained wind in the month of May – an impressive feat considering records have been kept there since 1897. The island gusted to 99 mph (159 mph) at about the same time.

Latest forecast path and intensity of center of Noul from the U.S. Joint Typhoon Warning Center. Circles denote uncertainty in location of center at each forecast time period.

Rainfall was locally heavy. Kabira, on the north side of Ishigaki Island, received over 4 inches of rain in three hours Monday evening as the center of Noul approached.
Satellite imagery Monday evening (local time) showed Noul as a much less formidable typhoon than it had been over the weekend. There was still a large blob of convection (thunderstorms) associated with the storm, but no discernible eye. However, Japanese radar continued to indicate a very well-defined eye and eyewall as it tracked through Japan's southern islands and past Okinawa. That eyewall began to erode late Tuesday morning (local time) as dry air intruded into the western and southern quadrants of the storm.
Western Pacific tropical cyclones, known as typhoons when they reach hurricane-equivalent status, can form any time of year.
Owing partially to this year-round calendar of potential development, roughly one-third of all the Earth's tropical cyclones form in the western Pacific Basin. On average, 25 tropical cyclones form each year in the western Pacific Basin, with 15-16 of those strengthening to Category 1 equivalent typhoons.
(MORE: Hurricane Central | Tropical Update)
Check back with us at weather.com and The Weather Channel for the latest on this Western Pacific tropical cyclone.
Meteorologist Jonathan Erdman contributed to this report.

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