Typhoon Mindulle Rapidly Intensifies to Equivalent of Cat. 5 Hurricane

Typhoon Mindulle rapidly intensified to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Saturday night. At 11:00 p.m. EDT on Saturday the center of Typhoon Mindulle was located at latitude 18.7°N and longitude 136.8°E which put it about 510 miles (825 km) southwest of Iwo To. Mindulle moving toward the northwest at 4 m.p.h. (6 km/h). The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 195 m.p.h. (315 km/h). The minimum surface pressure was 915 mb.

Typhoon Mindulle continued to intensify rapidly over the Western North Pacific Ocean on Saturday night. A circular eye with a diameter of 18 miles (29 km) was present at the center of Mindulle. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Mindulle. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the typhoon. The removal of large amounts of mass allowed the surface pressure to decrease rapidly.

The circulation around Typhoon Mindulle was more than twice as large as the circulation of Hurricane Sam which was over the Atlantic Ocean. Winds to typhoon force extended out 50 miles (80 km) from the center of Mindulle. Winds to tropical storm force extended out 210 miles (340 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Mindulle was 35.0. The Hurricane Size Index (HSI) was 19.4 and the Hurricane Wind Intensity Size Index (HWISI) was 54.4.

Typhoon Mindulle will move through an environment capable of sustaining a powerful typhoon during the next 36 hours. Mindulle will move over water where the Sea Surface Temperatures are near 30˚C. It will move into a region where the upper level winds are weak and there will be little vertical wind shear. Typhoon Mindulle may be near its peak intensity. If the inner end of a rainband wraps around the existing eye and eyewall, then concentric eyewalls could form. That structure would start an eyewall replacement cycle that could cause Typhoon Mindulle to weaken. Typhoon Mindulle will move slowly. The strong winds in Mindulle could mix cooler water to the surface. That would also cause Mindulle to weaken.

Typhoon Mindulle will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next several days. The high will steer Mindulle slowly toward the northwest during the next several days. On its anticipated track Typhoon Mindulle could be west of Iwo To in three days.