Typhoon Wipha (2007) - Meteorological History

Meteorological History

Typhoon Wipha originated from a tropical disturbance that was first identified by the Joint Typhoon Warning Center (JTWC) on September 13, 2007 roughly 1,435 km (892 mi) east of Guam. Deep convection had developed around an area of low pressure that formed within the disturbance. Low wind shear allowed the system to steadily develop as it moved northward. Late on September 14, convective banding features had formed around the center of circulation, prompting the JTWC to issue a Tropical Cyclone Formation Alert. Several hours later, the Japan Meteorological Agency (JMA) began monitoring the system as a tropical depression. At the same time, the JTWC declared that the disturbance had become Tropical Depression 13W. Shortly thereafter, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) also began issuing advisories on the developing depression, assigning it the local name Goring. Initially, a Tropical Upper Tropospheric Trough situated to the north of the depression suppressed convective development and outflow. However, late on September 15, this system weakened, leading to both the JTWC and JMA upgrading the depression to a tropical storm early on September 16. Upon being declared a tropical storm, the JMA assigned the name Wipha to the storm.

Throughout September 16, Wipha underwent a brief period of rapid intensification, with the JTWC upgrading it to a Category 1 hurricane, on the Saffir–Simpson Hurricane Scale, within 12 hours. The intensifying system maintained a northwesterly track in response to a subtropical ridge over the northwest Pacific. Early on September 17, Wipha was upgraded to a typhoon as 10-minute sustained winds reached 120 km/h (75 mph). A second round of rapid intensification took place through most of the day, leading to the typhoon attaining its peak intensity late on September 17 with winds of 185 km/h (115 mph ) and a barometric pressure of 925 mbar (hPa; 27.31 inHg). At the same time, the JTWC assessed Wipha to have nearly attained Category 5 status, peaking as a high-end Category 4 super typhoon with winds of 250 km/h (155 mph ). Upon reaching this intensity, Wipha became the second strongest storm of the 2007 Pacific typhoon season.

Not long after reaching its peak intensity, Wipha began to weaken as it started to interact with the high terrain of Taiwan. Early on September 18, PAGASA issued their final advisory on Typhoon Goring as it left their area of responsibility. Later that day, the center of the typhoon passed roughly 130 km/h (80 mi) north of Taipei, Taiwan. Continued weakening took place as the storm neared landfall in Mainland China. Around 1800 UTC, the eye of Wipha crossed the Chinese coastline near Wenzhou with sustained winds of 140 km/h (85 mph ). The JTWC assessed Wipha to have made landfall as a low-end Category 3 typhoon with winds of 185 km/h (115 mph ). Rapid weakening took place as the storm moved further inland. The JTWC issued their final advisory on Wipha during the afternoon of September 19 as they classified the system as an extratropical cyclone. However, the JMA continued to monitor the system as a tropical depression until September 20. At this time, the remnants of Wipha had entered the Yellow Sea and accelerated northeastward towards the Korean Peninsula. The extratropical remnants of Wipha persisted for several more hours before dissipating off the coast of North Korea that afternoon.