Black Wednesday Swell for North Atlantic

The North Atlantic is developing its first winter super storm. A rapidly deepening low pressure system is forecast to bottom out at 930 millibars and impact Northern Europe in the middle of next week with waves propagating throughout most of the Atlantic's western fringe.

Whilst storms on this scale are difficult to surf at their full intensity (often excepting Mullaghmore) the magnitude is impossible to ignore. Last year we regularly saw hurricane force systems like this with names like Hercules breaking records and sea defences, cutting off train lines, and reshaping our coastline. For surfers it is often a case of seeking shelter, or for Black Wednesday, heading south to the lower reaches of Europe / North Africa should score you cleaner waves.

Our new storm tracking system (available shortly) hooks directly into our global wave model and detected this storm on the radar almost a week ago.
© 2014 - magicseaweed

Detailed analysis

Ben Freeston, MSW Head Forecaster
Where a storm might typically cool as it gets closer to becoming reality the last 48 hours have seen model forecasts intensify the call for a giant North Atlantic storm early next week. While differing models have been agreeing on the storm for at least the last 48 hours, this morning we see both this agreement and encouraging signs hinting to the storm's physical development. The latest satellite images show the existence of a predicted cluster of storm activity in the Mid Atlantic that's the precursor to a developing low forecast to be an integral part of our super system.

Checking model data from different agencies is a key part of the validation process.

With high pressure dominant over the Azores and forecast over the Eastern United states our fledgeling system should build along the warm front moving north as a small, relatively weak low pressure system. At the same time another equally weak low pressure develops as normal in the Labrador Sea. Each on their own is nothing special but what computer models are seeing next is the really interesting bit - rapid intensification to a low of a forecast 930mb east of Greenland as the two come together. Exacerbated by the tip jet effect this is predicted to set up a broad band of fetch the full width of the North Atlantic, some 2000 miles. Around southern Greenland these winds are forecast well into the hurricane force range.

The usual challenges remain at this range. We're reliant on the development of two separate systems and a track that'll allow for this rapid cyclogenesis when they meet.
With forecast sea heights at peak now touching 60ft comparisons, even this early, with last year's Hercules super storm aren't unreasonable. While that was exceptional for its size (a modelled 68ft at peak) it also ran on an unusually southerly track. This storm follows a more typical path, which could leave winds in Mainland Europe more favourable if we do see the exceptionally large surf currently predicted.

The usual challenges remain at this range. We're reliant on the development of two separate systems and a track that'll allow for this rapid cyclogenesis when they meet. Things can and do change in the five day range - however the signals are as positive as they can be at this stage for this one and we've been talking to European big wave surfers over the last couple of days about the need to consider making solid plans and this storm is a candidate swell for the Big Wave World Tour event at Punta Galea.

One area in which there's the most model divergence at the moment is the state of the storm as it impacts the coast. Some model outcomes put a high pressure system over the Biscay coast holding off the worst of the winds (although NW onshores are still possible) but other variants have this system to the west and the low pressure extending south far enough to disrupt the French and Northern Spanish coast. This is an area in which we can reasonably expect change over the next week.

For Northern Europe it's a typical scenario of swell + storm, although at this size seeking shelter from both will be the order of business.

Jamie Mitchell dropping into a Belharra Hercules bomb.
© 2014 - Red Bull / Alex Laurel

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