Met Éireann has upgraded weather warnings to orange for Donegal, Mayo and Galway ahead of Storm Ciara.
In Donegal and Mayo, the forecaster says south to southwest winds on Saturday will reach mean speeds of 65-80km/h with gusts of up to 120 km/h.
This wind alert is in place from midday.
While in Galway, south to southwest winds will reach mean speeds of 65-80km/h with gusts of up to 120 km/h on Saturday.
This alert is in place for the county from 1.00pm.
Two other weather warnings are in place for wind and rain for the entire country.
Southerly winds will strengthen during Saturday, reaching speeds of 50-65km/h with gusts reaching 90-110km/h.
On Sunday, Storm Ciara will produce very strong winds with a risk of damaging gusts.
Over the weekend the combination of spring tides and high seas - as well as stormy conditions - will result in an elevated risk of coastal flooding.
This is especially the case along southern, western and north-western coasts.
Overnight and through Sunday morning, as Storm Ciara tracks eastwards to the north of Ireland, south to southwest winds will strengthen and become very strong and gusty - with possibly damaging gusts and with gales along coasts.
A band of heavy rain will move quickly south-eastwards across the country with a risk of localised flooding.
Showers will follow in the afternoon.
Through the late afternoon and evening, winds will become westerly and continue strong and very gusty, especially in coastal areas.