Summary
Walter was unusual in that it reached tropical cyclone intensity, decayed and then re-intensified to tropical cyclone intensity again. Walter also had a very unusual track and spent several days moving to the northeast and northwest.
A tropical low with an estimated central pressure of 1000 hPa was identified on 3 March near 14.6°S, 94.0°E. A high latitude cold front initially steered the low to the southeast. As the influence of the front weakened, a high pressure ridge that was being established behind the front caused the cyclone to change direction towards the southwest on 6 March.
Walter first reached cyclone intensity at 1800 4 March and reached maximum intensity (985 hPa) at 0700 6 March as it started moving towards the southwest. The cyclone then continued to move in a generally westerly direction and weakened; by 0600 8 March it had degenerated to a tropical low.
It tracked north northeast and weakened further until 1200 on 10 March when it first tracked to the north, then northwest and re-intensified so that by 1800 12 March Walter was again generating gales. It tracked west northwest and continued to intensify and crossed 90°E whereupon it was renamed Gregoria by the Mauritius Weather Service.
For more details see the TC Walter Report (pdf)