After intensifying earlier on Saturday, vertical wind shear began to affect Tropical Storm Niala and it turned westward.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Niala was located near latitude 16.9°N and longitude 152.8°W which put it about 245 miles (395 km) southeast of Hilo, Hawaii.  Niala was moving toward the west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 992 mb.  A Tropical Storm Watch remains in effect for Hawaii County.

A large upper level trough centered northeast of Hawaii is causing southwesterly winds that are blowing over Tropical Storm Niala.  The wind shear is blowing the tops off the thunderstorms that try to form near the center of circulation.  As a result the low level circulation is exposed on satellite imagery.  The effect of the wind shear will be to weaken Niala even though it is over warm Sea Surface Temperatures.

Since there are not tall thunderstorms near the center of circulation, it is being steered toward the west by winds lower in the atmosphere.  A general westerly motion is expected for the next several days and Tropical Storm Niala is likely to pass south of Hawaii.