Typhoon Hagibis Rapidly Intensifies Into Equivalent of Major Hurricane

Typhoon Hagibis rapidly intensified into the equivalent of a major hurricane east of the Marianas on Sunday night.  At 11:00 p.m. EDT on Sunday the cener of Typhoon Hagibis was located at latitude 15.3°N and longitude 148.8°E which put it about 320 miles (515 km) east-northeast of Guam.  Hagibis was moving toward the west-northwest at 19 m.p.h. (31 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 953 mb.

Typhoon Warnings were in effect for Tinian, Saipan, Alamagan and Pagan.  Tropical Storm Warnings were in effect for Rota and Agrihan.  A Tropical Storm Watch was in effect for Guam.

Typhoon Hagibis intensified very rapidly on Sunday night.  The maximum sustained wind speed increased from 75 m.p.h. (120 km/h) to 115 m.p.h. (185 km/h) in six hours.  A small circular eye formed at the center of Hagibis and a ring of strong thunderstorms surrounded the eye.  The strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of the typhoon.  Storms near the core were generating strong upper level divergence which was pumping mass away in all directions.  The removal of mass was allowing the minimum surface pressure to decrease rapidly.

The circulation around Typhoon Hagibis was increasing in size.  Winds to typhoon force extended out 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Hagibis was 20.2.  The Hurricane Size Index (HSI) was 18.1 and the Hurricane Wind intensity Size Index (HWISI) was 38,3,  Typhoon Hagibis was capable of causing major damage.

Typhoon Hagibis will continue to move through an environment very favorable for intensification for another 24 to 36 hours.  Hagibis 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.  Typhoon Hagibis could continue to intensify rapidly and it could strengthen into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale during the next 24 hours.  At some point a rainband is likely to wrap around the existing eye and eyewall and an eyewall replacement cycle will end the intensification of Typhoon Hagibis.

Typhoon Hagibis will move around the southwestern part of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Hagibis toward the west-northwest during the next 12 to 24 hours.  Hagibis will turn more toward the northwest in a day or so.  On its anticipated track Typhoon Hagibis will reach the Marianas in about 12 hours.  The center of Hagibis is likely to pass north of Saipan.  Typhoon Hagibis will bring strong winds and heavy rain.  It will be capable of causing major damage to the Northern Marianas.  Typhoon Hagibis could approach southwestern Japan in four or five days.