Typhoon Muifa intensified to the equivalent of a major hurricane south of the southern Ryukyu Islands on Saturday afternoon. At 5:00 p.m. EDT on Saturday the center of Typhoon Muifa was located at latitude 22.4°N and longitude 124.9°E which put it about 140 miles (230 km) south-southeast of Ishigaki, Japan. Muifa was moving toward the northwest at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 135 m.p.h. (230 km/h). The minimum surface pressure was 956 mb.

Typhoon Muifa intensified rapidly to the equivalent of a major hurricane over the Western North Pacific Ocean south of the southern Ryukyu Islands on Saturday. A circular eye with a diameter of 30 miles (50 km) was present at the center of Muifa’s circulation. 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 Muifa. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

The circulation around Typhoon Muifa increased in size when it intensified. Winds to typhoon force extended out 35 miles (55 km/h) from the center of Muifa. Winds to tropical storm force extended out 130 miles (210 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Muifa was 20.6. The Hurricane Size Index (HSI) was 12.6 and the Hurricane Wind Intensity Size Index (HWISI) was 33.2. Typhoon Muifa was capable of causing regional major damage.

Typhoon Muifa will move through an environment favorable for intensification during the next 24 hours. Muifa will move over water where the Sea Surface Temperatures are near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Typhoon Muifa is likely to intensify during the next 24 hours.

Typhoon Muifa will move around the western part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Muifa toward the north-northwest during the next 36 hours. On its anticipated track, the center of Typhoon Muifa could be near Ishigakijima within 36 hours. Muifa is likely to be the equivalent of a major hurricane when it approaches the southern Ryukyu Islands. The center of Typhoon Muifa could pass directly over Ishigakijima. Muifa will produce strong, damaging winds and locally heavy rain. Heavy rain is likely to cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 15W formed west-northwest of Wake Island. At 5:00 p.m. EDT on Saturday the center of Tropical Depression 15W was located at latitude 21.0°N and longitude 160.0°E which put it about 455 miles (735 km) west-southwest of Wake Island. The tropical depression was moving toward the northeast at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h). The minimum surface pressure was 1003 mb.