Powerful Typhoon Nangka is moving through the northern Mariana Islands. At 11:00 p.m. EDT on Wednesday the center of Typhoon Nangka was located at latitude 17.2°N and longitude 146.5°E which put it about 145 miles (240 km) north-northeast of Saipan and about 45 miles (75 km) southeast of Alamagan. Nangka was moving toward the west-northwest at 12 m.p.h. The maximum sustained wind speed was 145 m.p.h. (235 km/h) and there were wind gusts to 170 m.p.h. (275 km/h). Nangka is the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale. The minimum surface pressure was 929 mb.
Nangka has a very symmetrical structure and strong convection surrounds the eye. It is over warm Sea Surface Temperatures and it could intensify further. Upper level outflow from the eastern side of large Typhoon Chan-hom which is about 1200 miles (1940 km) west-northwest of Nangka could begin to create wind shear over the western side of Nangka. Eyewall replacement cycles could also produce fluctuations in intensity.
A subtropical ridge is steering Nangka toward the west-northwest and that steering pattern is expected to continue for another two or three days. On its anticipated track the core of Nangka will pass close to the islands of Guguan, Alamagan, Pagan and Agrihan. It could bring very strong winds and heavy rain to those locations on Thursday.