In-Fa Weakens to a Tropical Storm on Its Way to Iwo To

In-Fa weakened below typhoon intensity on Tuesday as it moved toward Iwo To.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm In-Fa was located at latitude 20.1°N and longitude 135.3°E which put it about 540 miles (870 km) southwest of Iwo To.  In-Fa was moving toward the northeast at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 994 mb.

A large upper level trough that extends south of Japan is producing strong southwesterly winds over the top of Tropical Storm In-Fa.  Those winds are causing strong vertical wind shear which is tilting the upper portion of the circulation of the tropical storm toward the northeast.  The stronger thunderstorms are all located northeast of the center of In-Fa.  It also appears drier air is wrapping around the southwestern part of the circulation.  The strong vertical wind shear will continue to weaken Tropical Storm In-Fa.  As it moves into a cooler environment In-Fa will gradually make a transition to an extratropical cyclone during the next 48 hours.

The upper level trough will continue to steer Tropical Storm In-Fa toward the northeast while it makes the transition to an extratropical cyclone.  On its anticipated track In-Fa could bring tropical storm force winds to Iwo To in 24 to 36 hours.