Meteorologists have revealed that a weakened high pressure belt has been the main reason behind this year's calmer southeast monsoon season.

According to Mr Robert Lajoie, the Climate Centre Manager for the National Meteorological Service, this year's calmer conditions have been the result of a reduction of the Mascarene Anticyclone.

Centred to the south-east of Rodrigues, the Mascarene Anticyclone is a belt of high pressure which is the driving force behind the Southeast Monsoon, the full force of which is usually felt during July and August.

The information provided by Mr Lajoie shows that throughout the months of July and August daily average wind speeds of under 10 knots are relatively uncommon, with the monthly averages closer to 12.5 knots.

However, between August 14 and 17 this year (which coincided with Lafet La Digue),  winds remained light at between 3.4 and 5.8 knots.

Equally unusual was the sea surface temperature, which, for the four days of this year's Lafet La Digue, reached almost 27.5 degrees centigrade, compared to the usual August average of 25.6 degrees.

The calm winds, clear skies and warm seas of the 2003 Lafet, were conditions far similar to those found in April.

According to Mr Lajoie the Mascarene Anticyclone was weakened during the period of Lafet La Digue by "Extra-Tropical Cyclones" moving from the Mozambique Channel, south of Madagascar and into the vicinity of the Mascarene Anticyclone, where both weather systems lost strength.

This loss of force of the Mascarene Anticyclone led to a drop in wind speeds over Seychelles and the resultant good weather.

Mr Lajoie also suggested that the warmer water that accompanied the festival was caused by the clear skies and a limited mixing of waters due to the calm conditions, not in the movement of areas of warm water, a theory which had been used by some when explaining the recent algal bloom.

Mr Lajoie supported this view with information from the U.S. National Oceanographic and Atmospheric Administration (NOAA), which showed no large scale anomaly in sea surface temperature movements evident in the region for the week centred on August 13.

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