Chances of racing in February

One month out from the AC33 start gun, meteorologist Roger Badham tells us of Valencia's weather in February

Just one month to go until the 33rd America’s Cup kicks off in Valencia now... Later today we can expect the Sailing Instructions for the race to be published, but in the meantime we thought we’d have a look at what the weather may be like next month.

Those who visited Valencia for the 32nd America’s Cup, from the Louis Vuitton Trophy starting in the late spring through to the Cup itself at the height of the summer, might be thinking ‘Mediterranean = shorts, T-shirts, sunglasses’, but this is unlikely to be the case come February, the shorts and T-shirts at least. At present there is torrential rain in Valencia and at night the temperature is dropping to near freezing with the possibility of snow on the surrounding mountaintops...

Looking back at the weather for the week around 8 February in past years:

In 2009 temp 0-18degC, mean wind speed 8.6 knots, max 26 knots (gust 33 knots), wind about 90% westerly
In 2008 temp 2-20degC, mean wind speed 3.7 knots, max 17 knots (gust 20 knots), wind about 75% westerly, 15% southeasterly
In 2007 temp 5-20degC, mean wind speed 5.9 knots, max 27 knots (gust 39 knots), wind about 80% westerly, 10% NE-SEerly
In 2006 temp 0-18degC, mean wind speed 3.2 knots, max 8.6 knots, wind about 70% westerly, 20% NE-SEerly
In 2005 temp 1-21degC, mean wind speed 3.2 knots, max 14.6 knots (gust 24 knots), wind about 40% westerly, 20% NE-SEerly



According to Roger ‘Clouds’ Badham, meteorologist with Emirates Team New Zealand, during February typically around five fronts will pass across Valencia over the course of the month. “They will close the place down for at least a day and a half to two and a half days depending upon the nature of the front and its severity.

“You have the pre-frontal flow which is coming up from the southwest and that, depending upon its configuration, can give quite strong winds off the Point of Denia [to the south of Valencia] and you get little lee eddies. But the post-front is the traditional one – where the flow is coming in from the west and the northwest.”

Typically there are two big flows that affect Valencia, both related to the same frontal conditions – the Mistral out of the Golfe du Lyon off southwest France and another down to Ebro Valley near Tarragona, to the north of Valencia.

“The Mistral out of the Golfe de Lyon bends down and comes right down, very rarely actually into Valencia, even if it is 50 knots, by the time it comes into Valencia you are struggling to get more than 20 knots out of it, as a ‘bent Mistral’,” states Clouds.

He warns though that while the Mistral winds may not reach Valencia, the sea from it does. “The flow coming down to Majorca and Ibiza can be very strong - 30-50 knots or whatever - and that’s only 80 nautical miles away, so you can get a very short nasty sea which pushes on to the Valencia beaches. Anything with that sort of wind will give a seaway which is short and very lumpy.” And definitely more than the 1m permissible in article 6.7 of the Notice of Race.

“In the winter the post frontal flow can be right across to Valencia, so you can get very strong west and WNWerly winds and they can be 20-30 gusting 40 knots - very gusty. Obviously that is an offshore breeze, so you are not getting much seaway, but the same flow can be pushing in a seaway [from th Mistral] against the strong winds coming out of there.”

So Clouds reckons that roughly 10 days a month are typically lost due to frontal activity in February and perhaps another day or two from the pre-frontal conditions, as even if the wind isn’t strong off Valencia, the seaway can still be quite lumpy due to what is occurring in the vicinity.

In the period between fronts, Clouds says that a sea breeze can develop, even in February, due to the water temperature being particularly cold. “The Mediterranean is a small body of water, so the water temperature there goes up and down remarkably. The minimum temperature is about 13-14 degC in the heart of winter, which is basically February and about the coldest it gets, while in August it is about the warmest and it can get up to 25 degrees - so a big range. It is warming at something like a degree a week – when we were doing the round robins. So in the non-frontal days you will get sea breeze and the days will be pretty good – you get a lot of bright blue sunny days, rather like the winter of Sydney or San Diego: beautiful, bright blue crystal clear sunny days. Typically day-night temperatures might be 6/8deg C to 18degC and the water temperature at 13-15degC so the land does warm up hotter than the water and you do get a sea breeze: you can sure feel it when the wind turns around, because in the offshore breeze in the afternoon at 1-2pm it is a balmy light wind, 15-18 and then the breeze turns around on shore and immediately the temperature plummets down to the water temperature which is 13-14 and it has got a real nip to it.”

Clouds describes the Valencia sea breeze as “benign” at this time of year, as it is even in the height of the summer. “It may only last for two or three hours and it might only be 5-12 knots. And as soon as the sun starts to go the breeze is just gone and you are back to the offshore flow.”

Aside from the stronger winds associated with fronts, the greater issue is likely to be complying with the Notice of Race’s maximum wave height of 1m. “You get a lot of very flat days - as long as they don’t count a very long period swell,” warns Clouds. The Notice of Race makes no mention of the wave period. “You can get a 1m swell with a 10 second period, which won’t be affecting anyone. It is the shortness of the period – which might be 6-8 seconds which is a swell coming from another place, as opposed to wind waves that are being generated at the place. If they take period into consideration then they’ll find sufficient days to race. Then you are just reliant on the little sea breeze in the afternoon or the offshore westerly which might be a bit fickle and silly.”

But guess what – the historical data from the buoy located 20 miles off Valencia suggests that typically in February the wind is less than 3m/s (5.8 knots) for more than 50% of the time... So even if the race does go 2-0 up to one of the teams, don’t assume this America’s Cup to be done and dusted in three days.