Super-typhoon NEOGURI hit in July 2014 Dr. Susanne Haeseler; updated: 11 July 2014

Introduction

At the beginning of July 2014, the first super-typhoon of the year 2014, NEOGURI, devel- oped across the western North Pacific. The typhoon first moved northwestward towards the southern , a chain of Japanese islands between the Japanese main islands and Taiwan (Fig. 1 to 3). On its way it reached maximum sustained 1-minute wind speeds of about 250 km/h. After crossing the island chain and weakening gradually, NEOGURI turned to northeastern directions. Downgraded to a tropical storm it crossed Kyushu and then moved along the southeastern coasts of the other main islands of Japan. In the course of 11 July 2014, NEOGURI weakened to a tropical depression. Meanwhile it had passed the southeastern part of the island of Honshu near and was located off the coast over the sea.

Fig. 1: Satellite image of super-typhoon NEOGURI across the Ryukyu Islands, acquired on 8 July 2014, 05 UTC. [Source: NASA, Earth Observatory]

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Fig. 2: Map of Japan. [Source: weltkarte.com]

The damage caused by NEOGURI in Japan due to strong winds with squalls, high seas and heavy precipitation led to floods and landslides. There were power outages, bus and train connections were interrupted, and flights were cancelled. Despite previous warnings and evacuations several people lost their lives.

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Fig. 3: Track of super-typhoon NEOGURI in the area Japan. Updated: 10 July 2014, 12 UTC. The observed track is marked by the black line, the forecast by the pink line. [Source: JTWC]

Wind, precipitation and air pressure

The following data of wind, precipitation and air pressure are only examples to demonstrate the impacts of typhoon NEOGURI.

Ryukyu Islands

An overview of the hourly precipitation totals on the Ryukyu Islands is given by the analysis chart valid for 8 July 2014, 22:30 UTC (Fig. 4). It shows a band of precipitation with high in- tensities (red).

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Fig. 4: Precipitation analysis for the area of Japan on 8 July 2014, 22:30 UTC (9 July 2014, 7:30 JST). (JST) = UTC + 9 hours [Source: JMA]

The development of precipitation, wind and air pressure on the Ryukyu Islands is illustrated by data from the weather station of Naha in Figure 5. During the crossing of super-typhoon NEOGURI, a total of 359 mm of rain fell within the 24-hour period from 8 July 2014, 00 UTC, to 9 July 2014, 00 UTC. This is more than twice the monthly average of 171 mm. On the 8th between 20 and 21 UTC, the rainfall was very intense as 76.5 mm fell within one hour. At that time, the centre of NEOGURI had already passed Naha (Fig. 5, bottom).

The highest wind speeds at Naha occurred when the air pressure reached its minimum of 980 hPa (Fig. 5, middle and bottom). The sustained 10-minute wind speed was temporarily more than 100 km/h.

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Fig. 5: Observations at Naha on the Ryukyu Islands from 7 to 9 July 2014. Time data in UTC. [Data source: JMA] Top: hourly precipitation (in mm). Middle: sustained 10-minute wind (in km/h). Bottom: air pressure (in hPa).

5 Islands of Kyushu and

The following precipitation totals were recorded during the 24 hours from 9 July 2014, 00 UTC, to 10 July 2014, 00 UTC:

Nagasaki (Kyushu) 70 mm Kagoshima (Kyushu) 150.5 mm Miyazaki (Kyushu) 52 mm Kochi (Shikoku) 56 mm

Already early in July, torrential rains had occurred on the Japanese island of Kyushu causing floods and landslides, e.g. at Nagasaki. At Nagasaki, 172 mm of rain was observed during the 48 hours to 4 July, 00 UTC. This is approximately half of the monthly average for July (334 mm). Until 7 July, 00 UTC, i.e. before the arrival of NEOGURI, an additional 123 mm fell, due to a front across Japan’s southern main islands. As soils were already saturated, the precipitation triggered by NEOGURI (see above) aggravated the situation.

Wave heights

Super-typhoon NEOGURI triggered waves of a height of more than 10 m in the neighbouring seas. The Joint Typhoon Warning Center (JTWC) reported significant wave heights of up to 12 metres on 7 and 8 July. The analysis chart of the Japan Meteorological Agency (JMA) in Figure 6a shows the distribution of the significant wave heights. The significant wave height is defined as the mean height of the highest third of all waves in an observational period, i.e. single waves were higher than the significant wave height.

Fig. 6a: Significant wave heights (in metres) in the seas around Japan on 08 July 2014, 12 UTC. The high waves were trig- gered by super-typhoon NEOGURI, the centre of which is located in the area of the maximum wave height. [Source: JMA]

6 Even after the weakening of NEOGURI waves of more than 5 m height occurred along the Japanese coasts (Fig. 6b).

Fig. 6b: Significant wave heights (in metres) in the seas around Japan on 10 July 2014, 00 UTC. The high waves were trig- gered by super-typhoon NEOGURI, which had been downgraded to a tropical storm at that time. [Source: JMA]

Typhoons in the region of Japan in July

In the waters around Japan typhoons are no rarity in July. The Japanese main islands are hit by very strong ones every several years. The last such event occurred in July 2011, when typhoon MA ON headed toward southern Japan. Super-typhoon MAN YI in July 2007 had a track similar to that of NEOGURI.

Sources and further information

. Deutscher Wetterdienst (DWD): Data archive. www.dwd.de . Japan Meteorological Agency (JMA): http://www.jma.go.jp/jma/indexe.html . Joint Typhoon Warning Center (JTWC): http://www.usno.navy.mil/JTWC/ . NASA: Neoguri (Northwestern Pacific Ocean) http://www.nasa.gov/content/goddard/neoguri-northwestern-pacific-ocean/ . NASA, Earth Observatory: Side Profile of Typhoon Neoguri. (July 5, 2014) http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=83993 . NASA, Earth Observatory: Typhoon Neoguri. (July 7, 2014) http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=83980 . NASA, Earth Observatory: Typhoon Neoguri. (July 8, 2014) http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=83995 . NASA, Earth Observatory: Typhoon Neoguri in Moonlight. (July 9, 2014) http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=83998

7 . Unisys: 2014 Hurricane / Tropical Data for Western Pacific http://weather.unisys.com/hurricane/w_pacific/2014/index.php . Unisys: Tropical Advisory Archive. http://weather.unisys.com/hurricane/archive/ . Weltkarte.com: Landkarten von Japan. http://www.weltkarte.com/asien/japan.htm

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