The first impact of a fresh swell steaming across the North Atlantic will be felt today in some spots. But, in a few days time, we're going to see another epic run rifling into some of the more prominent spots across Europe.
Now though? We're definitely in for a run that could cap out the winter season. “The upper atmosphere over the North Atlantic currently contains a large trough to the west and a ridge to the east,” says MSW forecaster Tony Butt.
“As a result, surface lows that develop near Newfoundland are deepening west of the Azores then shooting north towards Iceland, while local areas are mostly under the influence of high pressure.
“At the moment there is a large low in the middle of the North Atlantic, about 1,000 miles west of Ireland, moving quickly northwards. A strong fetch on its southeast flank is generating a large, long-period swell, the majority of which is propagating north towards Iceland. However, a large amount will still swipe west- and southwest-facing coasts of Europe.
“The swell will arrive at most spots sometime late Thursday, with long-period forerunners of over 20 secs., before the swell quickly fills in, peaks in most places on Friday morning and then tapers off into Saturday.
“Wave heights in Galicia and Portugal will hit 15 feet or so with moderate or fresh south or southeast winds. The swell will be big at Nazaré but once again the westerly direction won’t favour those epic A-frames.
“The west swell will probably hit southwest France much better than most of northern Spain, with spots like Guéthary and La Nord getting some super-clean swell of at least 10 feet with light offshore winds.
“In mid-areas such as Cornwall, also expect some good swell, with wave heights well over six feet early Friday, accompanied by fresh southeast winds. Further north in Ireland, west- and southwest-facing spots will be well over ten feet, accompanied by strong southerly winds. The swell will struggle to reach northwest-facing spots particularly in the north.
“The upper airstream shows a similar situation for the next few days at least (the upper airstream, having much less energy interchange with the land and ocean, changes more slowly than the surface flow). Consequently, there is another big low hard on the heels of the last one. This is expected to generate another long-period west or southwest swell for around Monday.”