Potentially catastrophic Typhoon Goni neared Luzon on Saturday morning. At 5:00 a.m. EDT on Saturday the center of Typhoon Goni was located at latitude 14.6°N and longitude 126.9°E which put it about 300 miles (485 km) east-northeast of Labo, Philippines. Goni was moving toward the west-southwest at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 180 m.p.h. (290 km/h) and there were wind gusts to 220 m.p.h. (355 km/h). The minimum surface pressure was 898 mb.
Typhoon Goni exhibited a double eyewall structure sometimes seen in very intense tropical cyclones. There was a small inner eye with a diameter of 6 miles (10 km). That eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that inner eyewall. A second, outer eyewall with a diameter of 35 miles (56 km) surrounded the inner core of Typhoon Goni. Storms near the core of Gone generated strong upper level divergence which pumped large quantities of mass away from the typhoon. The removal of so much mass allowed the surface pressure to remain very low. Bands of showers and thunderstorms were revolving around the core of the typhoon.
The circulation around Typhoon Goni increased in size when the double eyewalls formed. Winds to typhoon force extended out 35 miles (55 km) from the center of Goni. Winds to tropical storm force extended out 130 miles (210 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Goni was 42.2. The Hurricane Size Index (HSI) was 13.6 and the Hurricane Wind Intensity Size Index (HWISI) was 55.8. Typhoon Goni was capable of causing catastrophic damage.
Typhoon Goni will move through an environment favorable for a strong typhoon during the next 12 hours. Goni will move over water where the Sea Surface Temperature is near 30°C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. An eyewall replacement cycle could cause Typhoon Goni to start to weaken. If the original inner eyewall dissipates and convergence becomes concentrated into the new outer eyewall, then the wind speed will decrease. However, Goni is likely to maintain much of its intensity until it reaches Luzon.
Typhoon Goni will move south of a subtropical high pressure system over the Western North Pacific Ocean. The high will steer Goni toward the west. On its anticipated track Typhoon Goni will be near Cataduanes Island in 12 48 hours. Goni could be near Manila in 24 hours. Typhoon Goni is capable of causing catastrophic damage to Luzon. Goni could generate a storm surge of up to 20 feet (6 meters) along the coast of southeastern Luzon. Typhoon Goni will drop heavy rain over parts of Luzon and flash floods are likely.
Elsewhere over the Western North Pacific Ocean, Tropical Storm Atsani moved north of Yap. At 5:00 a.m. EDT on Saturday the center of Tropical Storm Atsani was located at latitude 14.6°N and longitude 138.2°E which put it about 1060 miles (1705 km) east of Luzon. Astani was moving toward the west at 17 m.p.h. (28 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1001 mb. Tropical Storm Atsani was forecast to move toward the northwest and to strengthen.