YOU don't have to spend much time on the forecast pages to have spotted the chance of a monster swell for Europe next week - the models have been hinting at it for days. With the first event of the European leg of the WCT kicking off and with MSW the official forecaster for the Quiksilver pro we're itching to shout about it. So why haven't we?
As a surf forecaster you're torn between two desires: firstly and most critically 'be accurate', but secondly and more subtly there's an imperative to make the call. To be the first. To spot the big swell or the big storm before anyone else. The problem is they're not really compatible. Being accurate in large part is about being honest because being honest is shouting about not just what you know, but what you don't know -- and for every forecast there's an element of uncertainty, when we deal with Hurricanes it's the lion's share.
So we've been biting our lips over Igor + Europe for almost a week now. Even as some crazy exciting numbers drop into the long-range model forecasts we've been nervous to make get too excited and here's why:
We all know that storms make surf and all things being equal stronger storms make bigger surf but the problem with Hurricanes is their size. Sure there's energy there and plenty of it but it's all packaged up so neatly that, even with Igor a giant by regular standards, there just isn't enough fetch for the wind to generate exceptional waves. To generate interesting swell a Hurricane relies on a phenomena knows as 'virtual fetch', a complicated way of saying that the Hurricane is travelling in the same direction as the waves it makes, so the wind keeps blowing and making them bigger. We need not only a powerful storm, but we need it to be heading in the right direction. To complicate things further the speed of the Hurricane comes into play - waves of different periods travel at different speeds - if the Hurricane travels too slowly the interesting long period waves race away before it can blow much energy into them. In fact for the perfect storm we need the Hurricane to track at exactly the right speed to impart extra energy into the peak period of the swell. The alternative for European surfers is normally to hope that as the storm heads north and cools it turns extratropical and we end up with a large conventional low following its normal track. This tends to mean we get surf and wind at best and certainly doesn't normally lend itself to that exceptional long period power.
So right now what do we know? We know we have a powerful Mid-Atlantic storm heading the wrong way for Europe and to see exceptional European surf we need the storm to start to change track. We need, sometime in the next 48hrs, Igor to start a move away from the US and in a direction that'll push size into the swell heading towards Europe. We also need an increase in speed, the storm is currently moving at about 12 knots, good for building up the 6-10 second period component but doing nothing much to help the 15-16 second period we hope to arrive as the bulk of the swell. Thirdly as it moves north into colder waters we need the storm to maintain it's intensity.
So will it? The consensus of the model forecasts is that the storm WILL track back towards France, it WILL speed up and it WILL maintain Hurricane intensity. Already this week we've watched the numbers calm from a crazy (but entirely possible) 10ft@16 to an actually more contestable 7ft@16 - our gut feeling based on everything we have to hand is that it'll cool further but that we're 70/30 odds on for a swell in the 4-8ft range with the power of that all important 15-18 second period slap bang at the start of the contest window. Pretty much the perfect recipe for the grinding shorebreak barrels that Hossegor's famous for -- if it comes to pass and the sand is there. We'll be back mid week to update the latest numbers (which we should be able to have much more confidence in) and of course the all important local winds...
(PS. Stay safe Bermuda - It seems pretty trivial to worry about the surf when you're taking the brunt of the storm and our thoughts are with you)