According to the Portuguese Institute of the Sea and Atmosphere (IPMA), the “low pressure system with tropical characteristics”, which has been named “Gaston” and was identified on 20 September, at 22:00 (21:00 in the Azores), located 1,595 kilometres west of the archipelago, with a displacement to the north northeast at a speed of 28 kilometres per hour.

It is expected to change its trajectory to east-northeast on Wednesday, reaching the islands of the western group from Thursday, 22 September. The central and eastern groups should be reached on Friday, September 23.