The sea swell is expected to peak today all along the west coast, writes Lorna Siggins, Marine Correspondent.
The Atlantic's long "fetch" and a continuous period of westerly winds are the main contributory factors to the severe weather alert issued for this weekend.
By "fetch", meteorologists and oceanographers mean the distance of open water that the wind has had to cross, influencing the dynamic of waves created.
"In our case, it's the distance between Canada and here - and that's quite a lot of fetch," Met Éireann senior forecaster Michael McAuliffe told The Irish Times yesterday.
Combine that with a broad area of very low pressure which has been sitting south of Iceland, and one can get severe conditions, he says.
"In this case, we've had westerlies blowing for a number of days this week, rather than the normal variable wind direction, and so the orientation has allowed a very large swell to build up."
This swell is expected to peak today during daylight hours along the entire west coast from Kerry to Donegal and will abate gradually on Sunday, he says.
However, the impact on the coast will vary from location to location, Mr McAuliffe explains. "I wouldn't be standing on a low cliff looking out to sea, for instance," he says.
Steeper beaches already washed by coastal erosion will also be most at risk.
The Irish Coast Guard and Irish Water Safety are advising people to avoid exposed coasts, cliffs, piers, harbour walls, all beaches and promenades, due to the predicted swell.
Met Éireann is not necessarily expecting that any records will be broken this weekend - but tide heights may cause flooding. Ireland is regarded as "low risk" for the tsunami-type waves which have hit southeast Asia, but Met Éireann is to head up an early warning system being developed.
NUI Galway geologist Prof Mike Williams has predicted that a tsunami or giant wave could reach Ireland within 2½ hours of a volcanic eruption on the Canary Islands. He maintains that Ireland's position on a "fairly stable" part of the Earth's crust is no guaranteed protection from extreme seismic phenomena - such as that predicted for the Canaries if the Cumbre Vieja volcano on La Palma erupts.
During research on links between seismic occurrences and historical reports of unusually large waves here, Prof Williams found references dating back as far as the Annals of the Four Masters. However, he also discovered that Ireland had been affected by the Lisbon earthquake of November 1st, 1755, in which more than 50,000 people died.
Karin Dubsky of Coastwatch Ireland says lack of planning for coastal zone management may exacerbate risk situations - and the situation has been compounded by the break-up of the Department of the Marine and dispersal of responsibility for sections of foreshore legislation.