a hot rock mantis production
your guide to the climate of Réunion Island
Ile de la Réunion
The original and most informative
English language guide to the island

Cyclones
a breath of fresh air
Reunion Island lies in the Southwest
                Indian Ocean Basin. The cyclone season is, officially,
                from November 15th 2014 to April 30th 2015 - with the
                exception for Mauritius and the Seychelles, for which it
                will end on May 15, 2015.. There are, on average, 10.4
                cyclones per season accounting for 12%
                of the Earth's total. Of these an average of 4.4
                are categorised as severe.
              
Names for cyclones 2014 - 2015
                beginning 15/11/14 and ending 30/04/15- Tropical storm
                are only named once they have reached the stage of
                "moderate tropical storm". Names are assigned by
                Sub-regional Tropical Cyclone Advisory Centre in
                Madagascar (for west of 55°E) or Mauritius (for
                55°-90°E). A new annual list is used every year. Those
                barred have been and gone, if coloured click for link.
              
Adjali Bansi Chedz
                Diamondra Eunice Fundi Glenda Haliba Ikola Joalane Kesha
                Lugenda  Mahara Nathan Oscar Puleng Quenelle
                Roselina Sitara Tarik Umali Vuntu Wezi Xolani Yolande
                Zita 
              
Current cyclone status - green- good, slightly yellow - be vigilant, orange - not so good, red - oh shit!
click for definition of status
A general introduction
A tropical cyclone is a type of
                low-pressure system which generally forms in the
                tropics. While some, particularly those that make
                landfall in populated areas, are regarded as highly
                destructive, tropical cyclones are an important
                  part of the atmospheric circulation system, which
                  moves heat from the equatorial region toward the
                  higher latitudes. 
              
Structurally, a tropical cyclone is a
                large, rotating area of clouds, wind, and thunderstorm
                activity. The primary energy source of a tropical
                cyclone is the release of heat of condensation from
                water vapor condensing at high altitudes. Because of
                this, a tropical cyclone can be thought of as a giant
                vertical heat engine. 
                
                The ingredients for a tropical cyclone include a
                pre-existing weather disturbance, warm tropical oceans
                (+-26° C surface temp), moisture, and relatively light
                winds aloft. If the right conditions persist long
                enough, they can combine to produce the violent winds,
                incredible waves, torrential rains, and floods
                associated with this phenomenon. 
                
                This use of condensation as a driving force is the
                primary difference setting tropical cyclones apart from
                other meteorological phenomena, such as mid-latitude
                cyclones, which draw energy mostly from pre-existing
                temperature gradients in the atmosphere. To drive its
                heat engine, a tropical cyclone must stay over warm
                water, which provides the atmospheric moisture needed.
                The evaporation of this moisture is driven by the high
                winds and reduced atmospheric pressure present in the
                storm, resulting in a sustaining cycle. 
The terms "hurricane" and "typhoon" are regionally specific names for a strong "tropical cyclone" . A tropical cyclone is the generic term for a non-frontal synoptic scale low-pressure system over tropical or sub-tropical waters with organized convection (i.e. thunderstorm activity) and definite cyclonic surface wind circulation..
Tropical cyclones with maximum sustained surface winds of less than 17 m/s (34 kt, 39 mph) are called "tropical depressions". Once the tropical cyclone reaches winds of at least 17 m/s (34 kt, 39 mph) they are typically called a "tropical storm" and assigned a name. If winds reach 33 m/s (64 kt, 74 mph)), then they are called:
Sources : AOML and Armaegeddon online
The last "real" cyclone to affect Reunion - Dina (in French)