AREAS on the western coast of Anglesey from Cemlyn Bay to Llanddwyn Island are under a flood alert.
An amber triangle flood alert warning on the Natural Resources Wales website indicates that flooding is possible in the next 24 hours and warns people to "be prepared."
The area affected includes the North West Wales coastline from the Menai Straits to Aberdyfi.
A tidal flood warning is also in place at Holyehad.
Natural Resources Wales said today, Saturday, that a tidal flood warning would be in force at Holyhead, for the next four days due to spring tides.
The Lleyn Peninsula and Cardigan Bay coastline are also under a flood alert.
Natural Resources Wales says on its website it will continue to monitor the situation.
The Met Office has also upgraded its wind warning to amber for North Wales until 9pm.
It comes as a yellow weather warning for wind, due to Storm Ciara, has been put in place until 11.59pm on Saturday, and covers all of North Wales, except Wrexham.
A yellow weather warning for wind, covering all of North Wales, is also in place for all of Sunday.
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