Hurricane Igor Alert

WITH eyes on a solid south swell due to light up the Trestles WCT comp for the end of the week the East Coast is set for its own blast with swell from two hurricanes in the Atlantic and a tropical storm likely in the Gulf.

An already active season shows no sign of slowing with Hurricane Igor maintaining category 4 status and showing little sign of retiring any time soon. Once again conditions are set to steer this one up the Eastern Seaboard and keep the odds of a landfall extremely remote. Live tracking HERE.

With Hurricane Danielle losing a little of her predicted power as she closed to the coast and Earl flirting almost too closely Igor looks, at the moment, to bring the best of both worlds with a comfortably offshore track and intense power. The latest models are showing swell distributed the breadth of the coast with conditions peaking at around the 10ft@15secs mark on Sunday but with the bulk of the fetch aimed squarely NW expect these numbers to be more likely realised from North Carolina north rather than in South Carolina and Florida. The bad news is that the same models are currently showing the storm beefing up a general North Westerly airflow bringing strong winds to most states, the exception being further south. The latest forecast is for this to move on by Monday so as always with this sort of swell you pick your window and most locations will have some kind of swell from Thursday all the way through to Monday to have a shot at a surf with the peak falling later in the weekend.

On top of this we've got Hurricane Julia behind. She's mostly going to be lost in the aftermath of Igor on the latest forecast but surfers in northern states and Canada can expect a potential small secondary pulse of swell on Igor's tail.

Gulf Coast surfers we've got a bubble of cloud in the Carribean right now that looks like it could go tropical and head over the Yucatan. Best case scenario is enough presence in the gulf to send small short range swell north for Texas - nothing that we'd be getting too excited about but one to keep an eye on.

Accuracy Update

We talk a lot in these updates about the 'model' numbers. In this case we're using the detailed North Atlantic Hurricane swell model run by the NOAA. We've talked in the past about the difficulties predicting the swell from small but incredibly intense tropical storms so thought it was worth a recap on the forecast VS the actual reading on the wave buoys from Earl as an example, here's the low down:

Central Florida Model forecast gave an impressive 11ft@15secs and the swell hit the offshore buoys at 11ft@17secs (there areslightly different ways the model and the buoy calculate period) which looks very tight. However the nearshore buoys show this almost halving in size as it moves into the shallow coastal shelf arriving on the beach at 7ft@17secs which is nearer half the model call. As these long period swells hit the beach they'll then change profile and increase in size considerably on the face and all these numbers are for the swell not the breaking wave.

North Carolina Model peaked at 17ft@15secs and the buoy at Diamond Shoals actually shows a crazy 27ft@16secs as the storm passed overhead. More sheltered buoys nearer the shore peaked at around 10ft@17seconds. So the forecast definitely under called here at the peak.

New Jersey Model suggested 10ft@14secs and the best buoy showed 10ft@17seconds. Looks pretty tight.

It's really worth noting that the swells of this size and power are feeling friction with the seabed a long way offshore. As soon as they start moving onto the shallower coastal shelf they're starting to reduce in size and the model isn't really cleverer enough to completely understand this. For most coastal locations the model will be over calling the swell by ignoring this final reduction in size, although as we mentioned above the face height of the final waves will be bigger than the final swell and this is the bit we're most interested in, we're also generalising whole sections of coast, the NC buoys show 27ft at Diamond Shoals and 10ft only 60 miles away on the Onslow bay buoy. None the less reassuring that looking at the correlation the good folk at the NOAA got it pretty tight for Earl - and as always the latest detailed breakdown of this information is available completely free of charge on MSW.