Typhoon Bolaven rapidly intensified to the equivalent of a major hurricane over the Western North Pacific Ocean north of Guam on Tuesday. At 5:00 p.m. EDT on Tuesday the center of Typhoon Bolaven was located at latitude 16.4°N and longitude 144.3°E which put it about 100 miles (160 km) northwest of Tinian. Bolaven was moving toward the north-northwest at 11 m.p.h. (17 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 959 mb.

A Typhoon Warning was in effect for Rota, Tinian and Saipan. A Typhoon Watch was in effect for Guam. A Tropical Storm Warning was in effect for Guam.

Typhoon Bolaven brought strong winds and heavy rain to Guam, Rota, Tinian and Saipan. The center of Bolaven passed between Rota and Tinian and the strongest winds likely occurred in those places. A weather station in Saipan reported a sustained wind speed of 49 m.p.h. (79 km/h) and a wind gust of 68 m.p.h. (110 km/h). A weather station at Guam International Airport reported a sustained wind speed of 32 m.p.h. (52 km/h) and a wind gust of 46 m.p.h. (74 km/h). That weather station also measured 4.54 inches (115.3 mm) of rain.

Typhoon Bolaven began to intensify rapidly as it moved west of the Marianas. A small circular eye with a diameter of 14 miles (22 km) developed at the center of Bolaven’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Bolaven. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

The size of the circulation around Typhoon Bolaven increased when it intensified on Tuesday. Winds to typhoon force extended out 25 miles (40 km) from the center of Bolaven’s circulation. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Bolaven was 20.6. The Hurricane Size Index (HSI) was 11.5 and the Hurricane Wind Intensity Size Index (HWISI) was 32.1.

Typhoon Bolaven will move through an environment favorable for intensification during the next 24 hours. Bolaven 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 Bolaven will intensify during the next 24 hours. Bolaven could intensify rapidly at times. Typhoon Bolaven could strengthen to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.

Typhoon Bolaven will move around the western part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Bolaven toward the north-northwest during the next 24 hours. On its anticipated track, the Typhoon Bolaven will stay west of the Marianas during the next 24 hours.