HURRICANE GISELLE, 22 February-4 March February 22-23rd: A depression developed within the ITCZ to the south of Chagos. It moved rapidly toward the west. February 24: The depression intensified and was located about 500 km north-east of the Cargados. It had a type of closed circulation which formed into tropical system Giselle. The system moved south-west at a speed of 20-25 km/h. February 25: Giselle passed east of St Brandon between 0600 UT and 0700 UT. The wind blew from the west-north-west at 25 knots and the barometric pressure continued to drop until 1300 UT. This indicated that the system was intensifying. The maximum wind occurred around 2100 UT (gusts reaching 62 knots). The system was moving slowly south-west, progressively intensifying. February 26-27: Giselle reached the hurricane stage. It continued moving slowly south-west (8 km/h). Strong winds were registered at about 300 km from the center, at Tromelin. The Reunion recorded moderate but irregular wind from the east sector. Maurice recorded winds blowing from the east-north-east at more than 50 knots. February 28: During the night, Giselle approached the Reunion. The east-south-east flow intensified. On the 28th at 0300 UT (07 hours local time), St Pierre and Gillot recorded average winds exceeding 30 knots with peaks reaching 45-50 knots. At the same time, the pressure dropped and the rainfall intensified. At about 0500 UT, Gillot registered even stronger winds reaching 60 knots, however, the maximum average wind occurred between 0600 UT and 0700 UT (36 knots). St Pierre recorded the strongest average winds occurring between 0700 UT and 0800 UT (maximum average wind: 42 knots; wind gust peaks: 65 knots). At 0800 UT, a scattering of cloud masses was visible to the north-west of St Denis. The winds weakened and the rainfall practically ceased. Giselle was found about 20 km off the north-west coast of the Reunion. After 0900 UT, the winds passed over the north-east sector along all of the northern part of the isle. They were particularly strong at Port de la Pointe des galets, where winds peaked at 180 km/h. The rainfall doubled in intensity. Along the south, storms battered the regions during the afternoon. After a slight rise in the barometric pressure at Gillot due to the dynamic compression, the pressure fell until 1400 UT (probably due to the terrain of the isle and the intensification of the cyclone). After 1500 UT, the pressure rose. The winds blew toward the north. February 29: During the morning, the winds weakened. The rainfall was abundant and covered the entire isle until March 1st. The center of the hurricane accelerated toward the south-west and located at about 500 km south-west of the Reunion. March 1st: During the day, Giselle curved west-south-west and threatened the Madagascan coast, at which it finally arrived on the following night, just south of Farafangana. March 2: The cyclone crossed over the southern part of Madagascar (30 km/h) and caused heavy wind and rainfall along the Fort Dauphin and Faux Cap regions. Giselle caused significant damage to the Reunion, particularly due to the torrential rainfall. The strong winds lasted for a significant amount of time. However, the sea swell was not important (less than 6 m), even when the center of the cyclone passed near the isle. Giselle's passage near the Reunion caused heavy rainfall, particularly along the eastern regions. The following data was recorded on February 28th (mm and 1/10): Belouve (alt. 1,500 m): 1,688.8 Cilaos (alt. 1,200 m): 1,160.0 Hell Bourg (alt. 980 m): 1,100.0 Plaine des Cafres (alt. 1,550 m): 576.0 Takamaka (alt. 850 m): 961.2 Ilet a Cordes (alt. 1,200 m): 985.2 La Nouvelle (alt. 1,400 m): 850.0 Gillot (alt. 10 m): 268.4 St Pierre (alt. 52 m): 142.5 The following data was recorded during the period of February 26-29th: Belouve: 2,708.1 Cilaos: 1,759.7 Hell Bourg: 1,620.0 Plaine des Cafres: 1,227.8 Takamaka: 1,618.7 Ilet a Cordes: 1,756.5 La Nouvelle: 1,770.0 Gillot: 379.0 St Pierre: 235.1 The amount of rainfall recorded at Belouve on Feb. 28th (1,688.8 mm) does not beat the record rainfall over 24 hours at the Reunion; on March 17th, 1952, 1,870.0 mm of rain was measured at Cilaos.