Typhoon Trami Moves Slowly Toward Okinawa

Typhoon Trami moved slowly toward Okinawa on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Typhoon Trami was located at latitude 21.5°N and longitude 129.1°E which put it about 345 miles (560 km) south of Okinawa.  Trami was moving toward the north at 3 m.p.h. (5 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 949 mb.

The structure of Typhoon Trami changed significantly during the past 48 hours.  A second eyewall replacement cycle produced a larger eye and a bigger circulation.  Very slow movement of Typhoon Trami allowed the wind to mix cooler water to the surface.  Cooler water meant that there was less energy in the upper ocean to fuel the circulation.  The combination of the eyewall replacement cycle and cooler water resulted in a reduction of the wind speed and the surface pressure increased.

Although it is not as strong as it was 48 hours ago , Typhoon Trami is still a large powerful typhoon.  Winds to typhoon force extend out about 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extend out about 225 miles (360 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Trami is 17.8.  The Hurricane Size Index (HSI) is 24.5 and the Hurricane Wind Intensity Size Index (HWISI) is 42.3.  Typhoon Trami is capable of producing widespread serious damage.

Typhoon Trami is likely to weaken slowly while it remains over the cooler water it has mixed to the surface.  When Trami moves north of that water in 12 to 24 hours, it will move into a more favorable environment.  Typhoon Trami will move over water where the Sea Surface Temperature is near 29°C.  It will still be in an area where the upper level winds are not too strong and there will not be much vertical wind shear.  The broad circulation and large eye will prevent rapid intensification, but Typhoon Trami could strengthen on Friday.

Typhoon Trami will still be in area where the steering winds are weak on Thursday.  It will move slowly toward the north during the next 12 to 24 hours.  Eventually a subtropical ridge over the Western North Pacific Ocean will begin to steer Typhoon Trami again.  Typhoon Trami will move toward the north at a faster rate on Friday.  On its anticipated track Typhoon Trami could be near Okinawa by late Friday.  Typhoon Trami could approach Kyushu in about 72 hours and it could move across Honshu during the weekend.