Typhoon Neoguri

Pre-Landfall 2 | Summary
Posting Date: July 8, 2014, 12:00:00 PM

Typhoon Neoguri made its closest approach to Japan’s southern Okinawa islands last night, lashing the islands with torrential rain and strong winds. After reaching wind speeds of nearly 180 km/h, Neoguri weakened over the past 12–24 hours and has now been downgraded to a moderate typhoon. Neoguri has encountered some drier air from the north, equatorward outflow has decreased, and sea surface temperatures are not quite as warm as yesterday (but still warm enough to sustain a tropical cyclone). Neoguri is projected to hit Kyushu Island early morning Thursday, July 10, local time.

Current Conditions

According to the Japan Meteorological Agency (JMA), the official reporting agency in the Northwest Pacific Basin, as of the July 8, 1500 UTC advisory, Typhoon Neoguri is located at 28.4°N latitude and 125.7°E longitude, or approximately 300 km northwest of Okinawa’s capital, Naha. The storm has a minimum central pressure estimated at 945 mb and maximum 10-minute sustained wind speeds estimated at 155 km/h, with gusts as high as 225 km/h. Neoguri still exhibits a well-defined, nearly symmetrical eye.

Reported Impacts

In advance of the storm’s arrival, more than 500,000 people were evacuated from Okinawa. According to the Okinawa Electric Power Company, more than 100,000 customers have lost power. Nansei Sekiyu KK, a Japanese oil refiner, reported that it had suspended operations in Okinawa. In Naha, trees have been uprooted, storefronts damaged, and lampposts blown over. Effects from the storm’s outer rain bands in Okinawa have caused Japanese officials to cancel flights there, leaving hundreds of passengers stranded. In addition, all ferries connecting islands within the prefecture have been grounded. The storm has resulted in one fatality.

Evacuation orders have also been put in place for thousands of people along the southern coastline of Kyushu because of the threat of storm surge.

The JMA issued an emergency typhoon warning for Okinawa and the Miyako Islands—the first time such a high-level warning has been issued since the alert system was introduced last August.

Forecast Track and Intensity

Neoguri is forecast to slowly weaken over the next 24 hours as it encounters lower sea surface temperatures, higher vertical wind shear, and begins interacting with an approaching trough from the northwest. Neoguri made its turn to the north yesterday and will continue on this northerly track before recurving more to the north-northeast and then turning to the northeast. In 36 hours, Neoguri is forecast to make landfall in southwestern Kyushu Island near the city of Kagoshima as a strong Category 1 or weak Category 2 typhoon. However, because of the orientation of Japan’s coastline, even slight changes in the forecast track may have significant implications for loss potential.

After that, Neoguri will weaken further as it encounters the rough terrain of Kyushu Island and will accelerate to the east-northeast as it continues its interaction with the trough and the mid-latitude westerlies. Neoguri is expected to undergo extratropical transitioning.

Wind Speeds and Precipitation Totals

According to the Tropical Rainfall Measuring Mission (TRMM) and Japan’s Automated Meteorological Data Acquisition System (AMeDAS), precipitation ranged from 100-200 mm (about 4 to 8 inches) across the Okinawa islands.

Neoguri has an expansive wind field. The highest 10-minute sustained wind speeds were observed on the right side of Neoguri over Okinawa and the islands directly to the west. Naha recorded a peak sustained wind speed of 103 km/h with a peak gust of 181 km/h. Kumejima Airport reported a peak sustained wind speed of 123 km/h with a gust of 166 km/h while Tokashiki, at an elevation of 220 meters, experienced the strongest recorded sustained and gust wind speeds of 122 km/h and 191 km/h, respectively.

Exposure at Risk

The vulnerability of buildings to flood damage varies by construction type. For a given flood depth, a residential wood-frame building is expected to sustain more damage than a residential masonry building. Concrete construction is less vulnerable to flood than steel or masonry. Commercial and apartment buildings usually have stronger foundations than residential buildings, and are thus better able to resist flood loads.

The majority of the residential buildings in Kyushu consist mostly of wood-frame construction. At the expected wind speed levels, these structures may experience moderate to high cladding and roofing damage, and some homes may be destroyed. For engineered buildings, such as reinforced concrete and steel building expected structural damage is very low to none. Commercial building cladding and roof coverings could experience moderate levels of damage.

In addition, some flood-related damage due to the heavy rain and storm surge may occur. The flood damage is usually driven by water damage to the machinery and stock. Building height also affects flood damage. Because damage is usually limited to the lower stories of a building, high-rise buildings will experience a lower damage ratio—the repair cost compared to the total replacement value of the building—than low-rise buildings because a smaller proportion of the building is affected.

Insurance Impact

Over the previous two to three days, large parts of western Kyushu have experienced heavy precipitation. Many regions are saturated and therefore any additional precipitation from Neoguri will exacerbate the flood potential in this region.

Flood insurance does not exist as a standalone policy in Japan. Instead, property owners can opt to purchase flood coverage as part of a standard fire insurance policy. In typical Japanese flood policy coverage, a specified payout is made only when actual damage falls within a specified range of loss.

AIR’s tropical cyclone team will continue to monitor Typhoon Neoguri as it approaches Kyushu’s coast and will provide additional information as events warrant.

Pre-Landfall 2 | Downloads
Posting Date: July 8, 2014, 12:00:00 PM