▁around ▁Mad agas car ▁west ward ▁to ▁the ▁east ▁coast ▁of ▁Africa . ▁Trop ical ▁cycl ones ▁in ▁this ▁bas in ▁are ▁monitor ed ▁by ▁the ▁Regional ▁Special ised ▁Meteor ological ▁Centre ▁in ▁Ré union . ▁ ▁__ TO C __ ▁ ▁Tim eline ▁ ▁Systems ▁ ▁Mod er ate ▁Trop ical ▁Storm ▁Al eng a ▁ ▁On ▁December ▁ 5 , ▁a ▁rapidly ▁developing ▁area ▁of ▁low ▁pressure ▁crossed ▁ 9 0 ° E ▁and ▁entered ▁La ▁Ré union ' s ▁area ▁of ▁responsibility . ▁Within ▁hours ▁of ▁moving ▁into ▁the ▁region , ▁the ▁J oint ▁Ty ph oon ▁Warning ▁Center ▁( J TW C ) ▁class ified ▁it ▁as ▁Trop ical ▁Cy clone ▁ 0 1 S . ▁By ▁this ▁time , ▁a ▁band ing ▁eye ▁feature ▁was ▁apparent ▁on ▁satellite ▁imag ery . ▁F avor able ▁atmos pher ic ▁conditions ▁allowed ▁con ve ction ▁to ▁increase ▁in ▁intensity ▁and ▁coverage ▁over ▁its ▁center ▁and ▁good ▁out flow . ▁Several ▁hours ▁later , ▁La ▁Ré union ▁reported ▁that ▁the ▁system ▁had ▁intens ified ▁into ▁a ▁Mod er ate ▁Trop ical ▁Storm , ▁with ▁the ▁Maur it us ▁Meteor ological ▁service ▁naming ▁it ▁Al eng a . ▁The ▁name ▁was ▁contributed ▁by ▁Ken ya . ▁Cont inu ing ▁to ▁rapidly ▁intens ify , ▁Al eng a ▁strength ened ▁into ▁a ▁severe ▁tropical ▁storm ▁later ▁that ▁day . ▁Although ▁predicted ▁to ▁intens ify ▁into ▁a ▁tropical ▁cy clone , ▁Al eng a ▁weak ened ▁near ▁m idd ay ▁December ▁ 6 , ▁and