Flannan Isles Lighthouse is a lighthouse near the highest point on Eilean Mòr, one of the Flannan Isles in the Outer Hebrides off the west coast of Scotland. It is best known for the mysterious disappearance of its keepers in December 1900. From what I read in the Wikipedia article the disappearance of the three lighthouse keepers occurred on the 15th of December or shortly thereafter.
The weather from the 15th to the 17th from what I can see in the reanalysis charts was quite rough to the west of the Hebrides, with a westerly gale on the 15th,that backed southwesterly by the 16th. The switch to a tropical maritime air mass would explain the poor weather conditions reported by the steamer “Achtor” later on the 15th. As for the men being swept off the island by a freak wave who knows, the gradients are tight so there must have been gale force winds at that time, but possibly not storm force.
