Typhoon Bart (1999)

Super Typhoon Bart (Oniang)

Typhoon (JMA scale)
Category 5 (Saffir–Simpson scale)
Super Typhoon Bart at peak intensity
Formed	September 17, 1999
Dissipated	September 30, 1999
(Extratropical after September 25, 1999)
Highest winds	10-minute sustained: 165 km/h (105 mph) 1-minute sustained: 260 km/h (160 mph)
Lowest pressure	930 hPa (mbar); 27.46 inHg
Fatalities	36 total
Damage	$155 million (1999 USD)
Areas affected	Japan
Part of the 1999 Pacific typhoon season

Super Typhoon Bart, known in the Philippines as Typhoon Oniang, was a powerful and destructive typhoon that occurred during the 1999 Pacific typhoon season. It was the only super typhoon of that year. The natural phenomenon reached "super typhoon" status on September 22, when it grew to comprise winds containing a force of 260 kilometres per hour (160 mph).

Super Typhoon Bart claimed at least two lives on the island of Okinawa and brought over 710 millimetres (28 in) of rain to the island. Kadena Air Base was badly damaged by the typhoon, with over $5 million of damage sustained by the base. Heavy flooding and landslides led to a death toll of 30 and over 1,000 injuries in Japan. Over 800,000 homes lost power, whilst 80 000 were damaged in the aftermath of the storm. The worst damage occurred in Kumamoto Prefecture on the island of Kyūshū, where 16 people died and over 45,000 homes were damaged.

Tropical Depression 24-W developed midday on September 17, to the east of Taiwan. JTWC and JMA both initiated tropical depression warnings on the developing low. The depression initially remained quasi-stationary in weak steering currents while located about 400 mi (640 km) east-northeast of northern Luzon. The development of this system was hindered somewhat due to northwest wind shear. This kept the center exposed from the deep convection. Around 1200 UTC on September 18, there were signs that the shear was beginning to lessen a bit, and by 1800 UTC, a tropical upper tropospheric trough (TUTT) was far enough west to lead to more favorable conditions for strengthening and JTWC upgraded the depression to Tropical Storm Bart early the next day.