 In an area of only moderate inhibiting atmospheric conditions, the low was able to steadily intensify, reaching tropical cyclone status on December 18 as it tracked southwestward.At 2100 UTC on December 19, Bruce moved into the area of responsibility of Météo-France after crossing 90°E with maximum sustained winds of 155 km/h (100 mph).Upon passage into the southwest Indian Ocean Bruce already had a well-defined eye and further strengthening was anticipated.