Typhoon Neoguri Weakens to Category 3, But Still a Major Flood Threat to Japan

The outer spiral bands of Typhoon Neoguri are lashing the large southern Japanese island of Kyushu as the storm heads north at 15 mph towards Japan. Despite seemingly favorable conditions for intensification on Monday and Tuesday morning, with low wind shear, very warm sea surface temperatures of 30 - 31°C, very warm waters extending to great depth, good upper-level outflow, and only modest amounts of dry air, Neoguri mysteriously weakened from a 155 mph super typhoon to a Category 3 storm with 120 mph winds in the 30 hours ending at 11 am EDT Tuesday morning. Satellite images Tuesday morning showed a continued reduction in the intensity and areal coverage of Neoguri's heavy thunderstorms. Neoguri passed through Japan's Ryukyu Islands over the past day, killing one person and injuring 25, but the eyewall missed making a direct hit on any island. Some notable wind and rainfall reports from the islands:

Peak winds: Sustained winds of 79 mph, gusting to 118.6 mph at Tokashiki Island (according to the Japan Meteorological Agency)
Peak winds at Kadena AB (Okinawa): 74 mph, gusting to 101 mph
Kadena AB rainfall since 8am Monday: 24.03 inches, with 10.02 inches in 6 hours from roughly 3-9 p.m. JST today, and another 12.73 inches from 9 a.m. - 3 p.m. JST today


Figure 1. Radar image of the outer bands of Typhoon Neoguri affecting southern Japan, at 12:10 am local time Wednesday, July 9, 2014. Image credit: Japan Meteorological Agency.

Forecast for Neoguri
Neoguri has been caught by a trough of low pressure and is expected to turn northeast towards the Japanese island of Kyushu, where the city of Nagasaki lies. A stalled stationary front over the island has been bringing flooding rains to Kyushu since Thursday; Ushibuka (in far southwest Japan) picked up 14.72 inches of rain over the past 48 hours. Nagasaki had upwards of 8 inches of rain on Thursday. With the soils already saturated from these heavy rains, the torrential rains from Neoguri are sure to cause significant flooding on Wednesday and Thursday. The latest 00Z and 06Z Tuesday runs of the European and GFS models showed landfall occurring between 00 - 04 UTC on Thursday. Ocean temperatures will cool and wind shear will rise as Neoguri approaches Japan, weakening the storm, and Neoguri is likely make landfall as a strong tropical storm or Category 1 typhoon. At this intensity, major wind damage would not occur; flood damage from heavy rains will be the main concern. Neoguri, pronounced "NAW-guh-ree", is named after the Korean word for raccoon dog. It is also a brand of ramen noodle in Korea.

Links
Japanese radar
Official Neoguri forecasts from the Japan Meteorological Agency

Neoguri's eye has a wrinkle
Neoguri's displayed an unusual "wrinkle" in satellite images taken the past three days--a sharp line radiating out from the northern eyewall, where an interesting "cliff" of clouds had formed. The cause of this "cloud cliff" is unknown, but it is not uncommon to see them in Western Pacific Super Typhoons. Similar eyewall "cloud cliffs" were observed in 2012 in Super Typhoon Bopha (visible on the south side of the eye in this blow-up image from the University of Wisconsin CIMSS Satellite Blog ), and in Super Typhoon Jelawat (visible on the north side of the eye.)


Figure 2. ESA astronaut Alexander Gerst tweeted this photo of Typhoon Neoguri's "cloud cliff" from the International Space Station at 7am EDT July 8, 2014. At the time, Neoguri was a Category 3 typhoon with 125 mph winds.


Figure 3. ESA astronaut Alexander Gerst tweeted this photo of Typhoon Neoguri's "cloud cliff" from the International Space Station at 5am EDT July 8, 2014. At the time, Neoguri was a Category 3 typhoon with 125 mph winds.


Figure 4. NASA astronaut Reid Wiseman tweeted this photo of Typhoon Neoguri's "cloud cliff" from the International Space Station at 5:55 pm EDT July 7. At the time, Neoguri was a Category 3 typhoon with 125 mph winds.


Figure 5. Infrared VIIRS image of Neoguri taken at 12:53 am EDT July 7, 2014, showing the "cloud cliff" along the northern eyewall. Image credit: Dan Lindsey, NOAA/CIRA.

Jeff Masters