Tropical Storm Hagibis formed east of the Marianas on Saturday. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Hagibis was located at latitude 15.0°N and longitude 155.0°E which put it about 735 miles (1185 km) east of Guam. Hagibis was moving toward the west at 21 m.p.h. (34 km/h). The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h). The minimum surface pressure was 993 mb.
More thunderstorms formed near the center of a low pressure system east of the Marianas and the Japan Meteorological Agency designated the system as Tropical Storm Hagibis. The circulation around Tropical Storm Hagibis was organizing quickly. The inner end of a band of showers and thunderstorms wrapped around the southern and eastern sides of the center of circulation. Bands of showers and thunderstorms formed and were revolving around the center of Hagibis. Storms near the center began to generate upper level divergence which pumped mass away from the tropical storm. Winds to tropical storm force extended out 110 miles (175 km) from the center of circulation.
Tropical Storm Hagibis will move through an environment very favorable for intensification. Haigibis 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. Tropical Storm Hagibis will continue to strengthen and it could intensify rapidly once an eye and an eyewall create a fully developed inner core. Hagibis could strengthen into a typhoon within 24 hours. It could be the equivalent of a major hurricane in two or three days.
Tropical Storm Hagibis will move south of a subtropical ridge of high pressure over the Western North Pacific Ocean. The ridge will steer Hagibis toward the west during the next 24 to 36 hours. Hagibis will move toward the northwest next week when it gets closer to the western end of the subtropical ridge. On its anticipated track Tropical Storm Hagibis could reach the Northern Marianas within 36 hours. Hagibis could be a typhoon when it reaches the Marianas.