Typhoon Bualoi Strengthens as it Approaches the Marianas

Typhoon Bualoi strengthened as it approached the Marianas on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Bualoi was located at latitude 14.5°N and longitude 147.8°E which put it about 175 miles (285 km) east-southeast of Saipan.  Bualoi was moving toward the northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 967 mb.

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

Typhoon Bualoi strengthened quickly on Sunday.  A small circular eye developed at the center of Bualoi.  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 the typhoon.  Storms near the core were generating upper level divergence which was pumping mass away from Bualoi in all directions.

The circulation around Typhoon Bualoi was relatively small.  Winds to typhoon force extended out 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out 130 miles (215 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Bualoi was 16.5.  The Hurricane Size Index (HSI) was 9.8 and the Hurricane Wind Intensity Size Index (HWISI) was 26.3.  Bualoi was capable of causing localized serious damage.

Typhoon Bualoi will move through an environment favorable for intensification for another 36 to 48 hours.  Bualoi will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Bualoi will continue to intensify and it could strengthen into the equivalent of a major hurricane during the next 12 to 24 hours.

Typhoon Bualoi will move around the western end of a high pressure system over the Western North Pacific.  The high will steer Bualoi toward the northwest during the next 48 hours.  The typhoon will move more toward the north when it reaches the western end of the high pressure system.  On its anticipated track the center of Typhoon Bualoi could pass near Saipan in about 12 hours.  If the center passes near or over Saipan, then there will be winds of typhoon force.  However, since the circulation around Bualoi is fairly small, if the typhoon passes north of Saipan, it will receive much weaker winds.  Typhoon Bualoi could be near Iwo To in less than three days.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Neoguri was moving toward Honshu.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Neoguri was located at latitude 29.5°N and longitude 133.6°E which put it about 600 miles (965 km) southwest of Tokyo, Japan.  Neoguri was moving toward the north-northeast at 22 m.p.h. (35 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 989 mb.  Tropical Storm Neoguri could pass close to the coast of Honshu near Tokyo in about 24 hours.