BERTIE

History

Severe Tropical Cyclone Bertie–Alvin developed from a weak tropical low that persisted on 17 November 2005 at a low latitude approximately 740 kilometres west-southwest of Sumatra. The Bureau of Meteorology's TCWC Perth issued a gale warning on 18 November as small circulations within the system gradually organised into a well-defined centre, and the system was officially named Tropical Cyclone Bertie on 19 November, around 835 kilometres northwest of the Cocos Islands. Tracking southwestward around a mid-level ridge, Bertie steadily intensified and reached Severe Tropical Cyclone status on 21 November.

As Bertie approached the 90°E boundary between TCWC Perth and Météo-France Réunion (MFR) jurisdictions, it turned due southward and briefly remained in Australian responsibility before crossing into the MFR's area on 24 November, where it was renamed Intense Tropical Cyclone Alvin. At peak intensity, the MFR estimated maximum winds of 185 km/h, while the JTWC assessed winds of 210 km/h, equivalent to a marginal Category 4 on the Saffir–Simpson scale. After crossing into MFR jurisdiction the storm turned northwest and weakened under unfavourable conditions. The JTWC issued its final advisory on 26 November, and MFR discontinued advisories two days later. The remnant system dissipated on 3 December. Bertie–Alvin remained over open ocean throughout its life and did not make landfall.

Sources: Bureau of Meteorology report Wikipedia