 The final storm of the season formed in the Australian basin , and like Harriet @-@ Heather also originated out of the monsoon trough . On April 7 , a tropical low developed northeast of the Cocos Islands , and gradually intensified while moving southward , becoming Tropical Cyclone Jane the next day . The JTWC classified it as Tropical Cyclone 29S . A ridge to the south turned the storm to the west on April 11 . The cyclone intensified further , developing an eye , and crossed into the south @-@ west Indian Ocean on April 13 . At that time , the MFR renamed Jane as Tropical Cyclone Irna . Late on April 13 , the agency estimated peak 10 ‑ minute sustained winds of 140 km / h ( 85 mph ) . The next day , the JTWC estimated Irna reached peak 1 ‑ minute winds of 220 km / h ( 140 mph ) . Subsequently , an approaching trough turned the cyclone to the south and increased wind shear , which caused weakening . The eye dissipated , and Irna soon weakened below tropical cyclone status . On February 17 , Irna weakened into a tropical depression . The next day , the JTWC discontinued advisories , and on April 19 , Irna crossed back into the Australian region , dissipating on April 20 . 
