Tropical Storm Fengshen Forms East of Northern Marianas

Tropical Storm Fengshen formed east of the Northern Marianas on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Storm Fengshen was located at latitude 17.1°N and longitude 157.1°E which put it about 805 miles (1300 km) east of Saipan.  Fengshen was moving toward the west-northwest at 18 m.p.h. (30 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1000 mb.

More thunderstorms developed near the center of a cluster of thunderstorms east of the Northern Marianas on Tuesday and the Japan Meteorological Society designated the system as Tropical Storm Fengshen.  The distribution of thunderstorms around Tropical Storm Fengshen was asymmetrical.  Stronger thunderstorms were occurring in bands in the western half of the circulation.  Bands in the eastern half of the tropical storm consisted primarily of showers and lower clouds.  Fengshen was moving south of an upper level ridge over the Western North Pacific Ocean.  The ridge was producing easterly winds which were causing moderate vertical wind shear.  The wind shear was contributing to the asymmetrical distribution of thunderstorms.

Tropical Storm Fenshen will move through an environment favorable for intensification during the next several days.  Fengshen will move over water where the Sea Surface Temperature is near 29°C.  The upper level ridge will continue to cause vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be strong enough to prevent intensification.  Tropical Storm Fengshen will intensify gradually and it could strengthen into a typhoon during the next two to three days.

Tropical Storm Fengshen will move around the western end of the ridge over the Western North Pacific.  The ridge will steer Fengshen toward the west-northwest during the next 24 to 36 hours.  Tropical Storm Fengshen will move more toward the north in about 36 hours when it reaches the western end of the ridge.  On its anticipated track Fengshen will pass northeast of the Northern Marianas.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 27W developed east of Luzon.  At 4:00 p.m. EST on Tuesday the center of Tropical Depression 27W was located at latitude 12.1°N and longitude 130.9°E which put it about 315 miles (510 km) east of Laoang, Philippines.  The depression was moving toward the west at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1004 mb.