A southwesterly gale is set to hit Barra and South Uist over Wednesday.
The Met Office issued a yellow "be aware" alert for the southern tip of the Western Isles.
It will be blustery from the morning with conditions expected to become severe in exposed areas during the afternoon and evening.
Forecasts suggest gusts of 50-
The Met Office said winds will veer to the west in the evening before easing in the early hours of Thursday.
Heavy, blustery showers or some longer spells of rain could also lead to some surface water flooding on the roads especially over
Frequent showers or some longer spells of rain may lead to some localised surface water flooding, given the very wet state of the ground.
Cal Mac said the MV Isle of Arran is on amber alert and the morning sailings from Lochboisdale and Castlebay may be disrupted or cancelled due to a forecast of very rough seas and high winds.
The Clansman's outbound voyage from Oban may also be disrupted.
Gale forecast for South Uist and Barra
17 November 2015