Over the next couple of days the system moved southwards towards the Australian state of Kimberly .
Over the next couple of days the system intensified gradually before it was declared a category 1 tropical cyclone and named Errol by the BoM early on 15 April .
Over the next couple of days the system moved southwards towards the Australian state of Kimberly and intensified gradually before it was declared a category 1 tropical cyclone and named Errol by the BoM early on 15 April .