However, soon after this, the problems began to gradually intensify.

The system gradually intensified as it moved slowly towards the west.

The storm gradually intensified as it moved towards the northwest.

I shook my head, not sure whether she would be able to see the movement yet against the gradually intensifying glow.

The storm slowly drifted to the west and kept on intensifying gradually.

Moving steadily southwest, it gradually intensified, only to turn west on December 5.

After forming, the system gradually intensified and became a tropical storm early on September 20.

For much of its duration, the storm moved toward the northwest, gradually intensifying.

The system intensified gradually as it began to track quickly westward toward the Philippines.

Forming on August 8 from an area of low pressure, the system gradually intensified into a tropical storm.