It is highly unusual to have three hurricanes in the Atlantic basin at the same time (at left Katia, at right Irma, Jose is not on this image)- and even rarer for them all to be expected to make landfall on the same day! Hurricane names are organised alphabetically throughout the year – with the first hurricane of 2017 called Arlene, followed by Bret, Cindy and so on. This means hurricanes Irma, Katia and Jose had eight storms before them this season. However, the consequences of the six storms are completely different. However, Irma is the deadliest of the lot.