Wild seas and very strong winds are forecast over the next two days as a succession of deep Atlantic depressions batter the west coast.
Wind speeds up to 75mph are expected in the Western Isles.
The Met Office has issued a weather warning over Saturday and Sunday.
Strengthening winds over Saturday will peak at a force eight gale for some hours.
A lull on late Saturday into the early hours will not last too long before the conditions intensify again, with violent winds expected for a period on Sunday.
Powercuts are possible and some coastal routes and sea fronts could be affected by spray or large waves.
Cancellations and disruption to island ferries are inevitable.
Periods of heavy rain on already well saturated ground risks localised flooding and hazards to drivers and pedestrians.
The Met Office said: “A belt of very strong and possibly squally southerly winds will develop on Saturday morning with gusts of 60-
Winds will be cyclonic on Saturday, changing to come from the south to the east then south again, continuing to veer with fiercely westerly gusts into the evening as the low transits up the islands.
Conditions will worsen to gale 8 to violent storm 11. Gusts around 75 mph are anticipated across the Western Isles.
During the second half of Sunday, strong southwesterly winds are likely to develop across northwest Scotland. Gusts of 70 mph are likely, perhaps as high as 75 mph in more exposed locations.
Violent storm forecast for Western Isles
30 October 2020
