1. Although thunderstorm activity was initially minimal around the center of subtropical ridge . 2. Initially poorly organized, Pat headed east-northeast, south of a subtropical ridge . 3. Alpha was tracking along the southwest edge of a subtropical ridge . 4. With the subtropical ridge to the northeast, the nascent system moved northwestward initially. 5. The nascent system tracked generally west-northwestward around a subtropical ridge to its north. 6. The subtropical ridge also helps form most of the world's deserts. 7. Situated to the south of a subtropical ridge , the storm tracked west-northwestward to northwestward. 8. Nelson tracked westward, staying south of a large subtropical ridge . 9. Situated to the south of a strong subtropical ridge , the depression tracked rapidly westward. 10. The storm moved northwestward until a weakness in the subtropical ridge forced it eastward.
