Check out this chart issued by the NWS Ocean Prediction Center. It shows the developing North Atlantic 950mb low that set to bring huge surf to Europe over the weekend of the 15th/16th December. The outline, matching the size and shape of the continental US, shows just how huge the storm is – with an fetch stretching from Portugal to the Labrador sea:
Or for a slightly clearer view of the coast here’s the same storm on our charts:
The southerly Jetstream means swell will develop futher South than has been typical of recent storms, bringing larger swell to the coasts of Portugal and central Europe and opening up less exposed areas of Southern Ireland, Wales and England normally sheltered from more northerly systems. Satellite data already shows 45knt+ winds as the storm starts to form as forecast.
Swell size looks to plausibly exceed 20ft@17 seconds in Portugal, Northern Spain and France and hit 11ft@17 seconds even on the sheltered South coast of England and Wales. The southern trajectory means, for once, Western Ireland will offer swell in a similar size range not larger than these numbers.
Winds will be an issue for all locations with the likelihood of westerly or south westerly flow over most of the weekend as the storm impacts the coast. The north coast of Spain looks best situated, at a glance, to see both huge swell and potential for offshore conditions.
Big boards, extreme shelter and a rain coat all on the kit list from Friday until Monday with most surfers probably seeing the best of this swell as it drops into next week with less wind and more opportunities at exposed spots.