On 11 November a weak low developed in the monsoon trough, approximately 800 km to the north of Cocos Islands. Over the next three to four days, the system drifted slowly towards the south southwest, and reached cyclone intensity at 1800 UTC 14 November, when it was about 700 km to the west northwest of Cocos Islands. Tropical Cyclone Lee continued to intensify, reaching category two intensity at 0000 UTC 15 November, and crossed 90°E into La Reunion's area of responsibility at 0600 UTC 15 November.
Once west of 90°E, the cyclone was renamed Ariel . The cyclone remained at category two intensity for about another two days as it drifted slowly westward, and thereafter rapidly weakened to below cyclone intensity.
For more details see the TC Lee Report (pdf)
Track and intensity
All times in WDT - subtract 9 hours to convert to UTC.