https://phys.org/news/2018-08-hurricane-lane-unpredictable.html

"As Lane approaches Hawaii it will encounter a significant increase in wind shear – changes in wind speed and direction in the lowest 10 kilometers of the atmosphere – which we expect will cause the storm to weaken," Chavas said. "But since our models perform less well in predicting changes in intensity, people should be cautious."

Although models are generally good at predicting the path of a storm, they're not perfect, and even a small error could have a major impact. The storm brought in enormous amounts of wind and rain despite not coming particularly close to the island. The steep topography of Hawaii could make matters worse, potentially causing serious damage from flooding and erosion, said Chavas.