Hurricane Europe? Not Really...

Ben Freeston

by on

Updated 1111d ago

© 2017 - MSW

With hundreds of thousands of surfers on both sides of the Atlantic using MSW to keep in touch with their local surf forecast, it's no surprise that almost every Tropical Storm update we post has surfers in Europe asking 'will it hit us'. The answer, invariably, is an emphatic 'NO'. The reality is that the closest we ever come is an ex-hurricane transitioning into a normal cold core low pressure system and following the jetstream back east. With this being more typical in Autumn and this summer feeling unreasonably flat, here there's an understandable froth of for an Ex-Hurricane Bertha bringing some swell relief. Here we break down that scenario and contrast it with some analysis of the season so far for European surfers.

From a relatively early stage it looked increasingly likely that Bertha could transition from warm water fuelled Tropical storm to a normal cold core low pressure system. This extra tropical transition isn't itself unusual and in the best of cases, a relatively weak extra tropical storm merges with nearby systems and can give rise to particularly intense swell generating system for European waters. Briefly earlier in the week it looked as though we may see a scenario at the lower end of this scale. Yesterday we wrote of two possibilities, ex-Bertha merging with a low pressure pressure system already in play in the North Atlantic, or sneaking below this to bring wet and windy weather to France. The reality on the latest model updates is somewhere between these scenarios from a surfing perspective. The ex-Bertha system now looks increasingly likely to impact the UK as a satellite to the larger system, bringing onshore coastal winds in the 35mph+ range and large wind swell conditions to UK waters before then creating a weak fetch sending smaller surf to France and Spain.

The UK Outlook

Everything is relative. We honestly debated even writing a piece about an average wind swell of the type that wouldn't see most of us in the water on a normal Autumn day, but it's been flat here. Really really flat. As surf forecasters we're conscious how selective memory can be and how this can distort expectation. So we decided to break things down. Slow summers aren't themselves a surprise so how bad have things really been?

Average wave heights in the SW UK in July

Average wave heights in the SW UK in July

© 2017 - MSW / Channel Coast Observatory

In this chart you can see actual hour by hour wave heights in July in North Cornwall, UK. Also the average (mean) for the period of the sample and this year. On average we're looking down by about 20%. Of course averages don't really tell the story for a surfer. We don't surf average waves - we're looking to make the most of our time in the water by hitting the beach when something more interesting is happening. So we analysed the same data looking for the amount of time the surf would likely hit a certain size. This is more interesting:

Number of days swell is above a threshold in SW UK in July

Number of days swell is above a threshold in SW UK in July

© 2017 - MSW / Channel Coast Observatory

You can see most clearly the absence of those larger swells (2m+) which aren't unusual in July. As our forecaster Stefan Brunhuber breaks it down "Both this July and last are slower than the recent record. This is a sign of the low level of storm activity we've seen in the North Atlantic this summer and while certainly not exceptional in the longer term, does confirm our suspicions that it's been frustratingly flat!".

In this context even a 10ft@10 seconds swell is still something to get excited about so long as you can dodge the wind and we're pretty sure you've figured that out by now.

France / Spain Outlook

As these storm systems merge they are forecast to set up a long, weak area of south facing fetch West of Ireland. This will most likely bring mid sized, mid period swell to France and Spain (think 4-5ft@10 seconds) - welcome for sure but so far inside the range of normal as to be entirely unworthy of any excitement.

Although things may change, the reality is more muted than any connection with the word 'hurricane' might suggest but, set against a very flat summer, welcome none the less for those of us with surfing in mind.