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Image courtesy of JacquesVabre The new route route of the Trans-Atlantic Jacques Vabre takes some of the world best sailors aboard the fastest boats from Le Havre in France to Bahia, Brazil. From the map above you can see the dominant synoptic features: Low pressure east of the Bay of Biscay, high pressure over the Azores and trade winds down the Portuguese and West African coasts. The doldrums lie just north of the equator and Ascension Island - a vital waypoint for the trimarans - sits just to the south of the equator. A Synoptic smorgasborg New-look Jacques Vabre promises
tactical challenges October26, 2001 Short handed sailing is becoming 'le Rage de Vivre', thanks to the French maritime community and to witness proof look no further than this year's Trans-Atlantic Jacques Vabres ocean race. The legend two-handed yachting event leaves the French channel port of Le Havre and makes for Bahia, on the east coast of Brazil, partly tracing an old coffee trade route frequented by swift sailing clipper ships last century. Swift sailing remains, in fact it is far swifter, because the Transat Jacques Vabre is a grand prix event for Open class 60 foot trimarans and monohulls and Open 50 foot monohulls. This is the very best of fast sailing featuring some of the most talented professional sailors. Since its inception in 1993, this bi-annual yacht race has been dominated by French, Swiss, Belgian and Italian nationals - names familiar to those who follow the multihull Grand Prix circuit, the Vendee and Around Alone ocean races. But this year the lure of shorth-handed sailing has spread to include crews from Australia, the UK, Ireland, Poland and Finland. A total of 35 yachts are expected to contest the race, making this year's event the biggest, brightest ever. Image courtesy Offshore Challenges. Sailing at breathtaking speed: This point of sail is what Open 60 skippers adore. Hopefully trade winds along the West African coast will do their stuff during this year's Transat Jacques Vabre! New route, tricky waypoint This year's race also makes a departure from previous routes, ending in Brazil, rather than Cartagena, Colombia. It essentially traces the first half of the first leg of the Volvo Ocean Race, but takes place five weeks later - deeper into autumn and at a time when winter storms are centered further south - right in the path of these yachts leasving Le Havre to cross the notorious Bay of Biscay. Of special note, is an interesting waypoint for the faster trimarans - Ascension Island, located eight degrees below the equator along longitude 14 degrees west. Created primarily to engineer a closer finish between the multihulls and the Open 60 monohulls, Ascension Island should create a fascinating race south of the doldrums. It is imperative that all boats cross the Inter-tropical convergence zone at its narrowest - usually between 28-30 degrees west. However, with Ascension located east of this optimum crossing, it will be tempting indeed to cut the corner and sail closer to the rhumb line. Considering the trimarans don't need a lot of wind to sail fast, we might see some real race development as those behind challenge the leaders by staying east, pushing deeper into the doldrums in the hope of saving valuable miles. The danger of course, is that the closer the trimarans sail to the African coast, the less predictable wind is guaranteed. So this section of the race will come down to a synoptic chess game. If a trimaran can grab the enhanced north-easterly winds ahead of a tropical wave, for instance, a swift crossing of the ITCZ might result. On the other hand, if the wave isn't powerful enough to send the tri all the way through the doldrums, light winds behind it might trap the yacht while other competitors further west may have an easier crossing, albeit with more miles to sail. Tough competition The list of sailors preparing to start the Jacques Vabre is impressive indeed. Vendee Globe winner Michael Desjoyeux will navigate for Jean Luc Nelias, in Nelias' new Belgacom Open 60 tri. While the new boat is state of the art, and sports awesome foils, untested boats tend to break. So we will watch this talented pair with baited breath! Other skippers aboard brand-new boats include Lalou Roucayrol and Yves Parlier aboard Banque Populaire and Giovanni Soldini/Olivier Lozachmeur aboard Fila. How well will these state-of-the-art craft perform against tried and true players like Yvan Bourgnon and Yvan Ravussin's NC (formerly Bayer En France) or Francis Joyon and Thomas Coville's Eure et Loire? Only time will tell. Meanwhile, Ellen Macarthur, who placed second in the Vendee Globe will navigate for Alain Gautier aboard Foncia-Kingfisher and this pair are worth betting on. They won the Challenge Mondial Assistance earlier this year and have a strong track record. The boat, as well, is thoroughly tested. Watch this pair do well! While on the subject of the Open 60 tris, note how many monohull skippers are entering this exciting fleet: Coville, who won the Jacques Vabre two years ago aboard Sodebo; Soldini, who won the last Around Alone aboard Fila; MacArthur who we hear so much about these days and even her British colleague Emma Richards who passed Pete Goss' old Open 50 on to Alex Bennett and Paul Larsen (Ocean Challenger) in exchange for an old training tri under her sponsor Pindar Systems. Don't expect Richards - who won her class in the last Europe 1 New Man Star or her Finnish co-skipper Mikaela Von Koskull to hammer the fleet this time around, but in future ... We wait and see! In the Open 60 monohull division, Nick Maloney will be skippering MacArthur's old Kingfisher, renamed Casto-Darty-But, with MacArthur's shore manager Mark Turner as co-skipper. These two were part of the winning EDS Atlantic Challenge team and will be favourites for the Jacques Vabre, along with Roland Jourdain and Gael Le Cleac'h aboard Sill Plein Fruit, and Mike Golding/Marcus Hutchinson aboard Ecover. Keep an eye on Marc Guillemot's La Trinitaine - Team Ethyphar in this year's Transat Jacques Vabre. Routing notes Synoptic brief: 2) Prepare to cross the doldrums almost as soon as yachts leave the Channel, which means judging 10 days in advance what the ITCZ might be doing. In the meantime sail the bastard hard and harder! 3) Enjoy some fast reaching towards the Canary Islands and for a couple of days work the squall clouds in the North-East trade-winds between the Canary Islands and the Cape Verde Islands. 4) Cross the ITCZ as quickly as possible. But how can something that sounds so simple be so frustrating? From the start at Le Havre, the primary concern for Transat Jacques Vabre competitors is to escape the English Channel, and its complex tidal movements, round Brittany, leave the Bay of Biscay to port, and get into prevailing north-east trade winds around the Madeira Islands. It sounds all so easy, yet the first few days of this race could really sort the men from the boys. As the start of the Jacques Vabre takes place in late autumn, expect a powerful front or two to drop out of the North Atlantic and sweep over Ireland and the Bay of Biscay, with rapid wind shifts from south-east to south-west to north-west. If the North Atlantic storms track is further south, sailors might expect a low to develop east of the Portuguese coast and migrate north-east into the Bay of Biscay bringing gale force easterlies. Perhaps, as with the start of this year's Volvo, a monster low might develop mid-Atlantic to bring south-west headwinds to the fleet on their way to Cape Finisterre. In between these fronts and lows, expect a ridge of the Azores High to creep over the race course to plague yachts with lights airs. Once clear of this challenging zone, skippers and navigators will try to work their yachts far enough offshore to catch the northerly trades associated with the Azores High without getting caught in the light winds at its centre. Of equal concern is avoiding fluky winds in the lee of the north African coast. Looking ahead while driving hard Almost immediately, the Jacques Vabre sailors will begin analysing where to cross the inter-tropical convergence zone (ITCZ) otherwise known as the doldrums.
"It is very important to point the boat it in the right direction for the 12 to 18 hour gain while also satisfying the requirements for the big picture: The five to 10 day plan,"
says weather router Roger Badham. You know you're in the trades when large, puffy clouds drive towards you from the horizon, bringing rainbows and wind shifts. Some of these squall clouds rise to great heights - their cloud tops getting quite cold - and become visible on infra-red pictures taken from space as numerous white dots on the ocean. While yachts in the Jacques Vabre will only be amongst these squalls for a day or two on their rush south, there is time to play them to advantage. Transpac veteran Stan Honey is a master of squall tactics and notes that winds ahead of squall clouds tend to converge as they are sucked into updrafts preceding these mini-weather systems. Wind gusts, on the other hand, diverge in direction as the wind hits the sea surface and spreads out. Average winds in squalls, in the northern hemisphere, veer about 15 degrees to the right of the prevailing surface wind while behind these clouds winds can be dreadfully light - especially near dawn. Honey recommends grabbing any squall within reach when sailing aboard fast yachts - the extra wind will more than pay for the risk. Jibe back and forth in front of the squall, even if the jibe back may not be at a favourable angle because of the way the wind converges, or 'toes-in' in front of the updraft. The real trick with these squalls is to avoid getting becalmed directly underneath. Try to stay ahead of the wall cloud preceding the rain. Before you get wet, jibe out and away to sail back into the cooler winds preceding the squall. Finally, Honey notes that exiting the squall on port poll - in the northern hemisphere - will make your escape smoother. As squalls tend to move to the right of prevailing surface winds, jibing away from one of these blustery beasts on port pole will help to avoid getting caught behind and in light airs. Of course, in this Jacques Vabre, yachts will be sailing south and have no choice but to exit a squall on port pole! Mark Rudiger, co-skipper and navigator aboard Assa Abloy in the current Volvo race, notes that squalls remain unpredictable even to experienced eyes. "Sometimes they're forming, sometimes they're diminishing," he says. "Sometimes they move predictably, but then as they climb, and their tops touch upper level winds, they change direction and that's a hard one to call. "It really comes down to who wins the most squalls. If you're in the lead you don't want any - you want nice and steady conditions, but if you're behind you're looking for squalls all the time." According to veteran router Bob Rice, the ITCZ is best regarded as a climatic feature. There is no way to avoid it. Fortunately for modern sailors, their equipment has improved beyond the imagination of the first adventurers to cross ‘the line’. After all, it took Magellan’s expedition three weeks to get through this fluky zone, where north-east trades meet south-east trades to produce both violent squalls and dreaded calms. Rice notes that satellite imagery helps an awful lot to pick the best crossing point. Too close to the African coast, and the affect of land on the trade winds produces light and fluky air. Too far towards the Brazilian Coast33 and persistent northerly winds create havoc for skippers on their return leg up the Atlantic. According to Ken Campbell of Commanders Weather the first consideration when preparing to cross the ITCZ is to note the position and strength of the North Atlantic High. "If it is strong and to the south, then the doldrums will be narrowest due south of the maximum point of North Atlantic high pressure," he says. Somewhere to the west of middle - about 28 degrees west - usually results in a good crossing, and regions showing narrow bands of intense cloud are regarded as best. Too much cloud indicates dreadful doldrums, but a narrow band of activity indicates the kind of convergence useful to racing yachts. Remember: Convergence is the result of opposing winds colliding and being thrust upwards. Warm, moist air thrust upwards cools and produces cloud. In this case, navigators hope to find north-east trades colliding with south-east trades because at this point the doldrums are very narrow indeed. Active cloud along this zone also indicates squall activity, and while there is no wind underneath these miniature storms, there is plenty of it all around and careful skippers can leap from one to another, aiding their crossing. A major source of squall activity are tropical waves - inverted troughs of low pressure aligned north and south. Tropical waves start off as cloudy disturbances off the coast of west Africa and cross the Atlantic at 10 to 15 knots. “They can be quite useful," notes meteorologist and professional sailor Chris Tibbs. "A day or so before the wave arrives the skies tend to be quite a bit clearer and the wind can accelerate a little bit.” A tropical wave can also be where a hurricane develops, but Tibbs notes that for a hurricane to develop there has to be about seven pre-requisites, one of which is an upper air disturbance. “If everything else is there for a hurricane to form it may start to form on a tropical wave,” he says. While early October is certainly hurricane season, it is late in that season and the chances of any of the Volvo competitors running into a hurricane is minimal. Luck or skill? At the end of the day, it can be luck as much as skill which gets a boat through the ITCZ and into the South Atlantic. When Bob Rice routed Peter Blake’s ENZA, during its record circumnavigation, the 90 foot catamaran never hit the doldrums on its first leg south. The ITCZ was ‘bridged through’ and approaching the line, between 20 and 10 degrees north, the fast cat actually broke a 24 hour distance record of something like 520 miles. Rice's good forecasting continued right across the equator, with ENZA logging more than 500 miles for the day. On the other hand, while Rice was routing Olivier de Kersauson’s Sport-Elec on its circumnavigation, the maxi-trimaran hit an atrocious version of the doldrums on his leg north towards the finish. For 24 hours there was no wind above three knots. Despite the lack of wind, the tri managed to log 165 nautical miles, highlighting just how able these mega multihulls are in a variety of conditions. Rice recall’s the first time he routed for a full circumnavigation. This was in 1985 and his client was Dodge Morgan aboard American Promise, a heavy displacement monohull. The doldrums laid a trap, and the boat logged just 45 to 50 miles a day during the return crossing, despite a good passage southbound. "You have to treat ITCZ as a climate feature," says Rice. "You can try to minimise its impact, but you have little option. Between the African and Brazilian coasts there is a fairly narrow stretch of ocean and there are certain parts in which you can’t go or you will get horribly trapped. You end up with no more than a five to 10 degree slot in which to pass." Here's what Roger Badham has to say on the subject: "I use all the high resolution satellite pictures (infra red, water vapor and visible) for the mean inter-tropical convergence zone position, real time satellite derived winds and model-predicted winds. "We try to skirt all the major cumulonimbus (there are light winds directly underneath these thunderstorms) and use the edges (where downdrafts flow outwards), especially at night. Upper level winds and jet-stream cloud to the north are not used at all." This is a seriously difficult ocean and the region to the west of the South Atlantic High, along the coast of Brazil, is the worst. Roger Badham describes the region like this: " The east coast of Brazil is a tricky spot. In fact, anywhere north of 35 degrees south, along the eastern seaboard of South America is tricky. Heat lows come out and interact with fronts. Tropical systems can interact with frontal systems and trades along the top part of the Brazilian coast are tricky. They sometimes fire and sometimes don't. " © Jamie Brown/weather-wise.com 2001 Hot links for the east Atlantic: The UK's met office offers terrific weather images and information, starting with this animated satellite image of the eastern Atlantic and Europe, updated every six hours.Check out winds in more detail with isobars included, in this
cloud
and pressure composite image. For an animated look at how winds behave, complete with colour-coded isobars, view this three-day animated pressure forecast. View the east Atlantic in infra-red from the UK's met office. Surface pressure for the eastern North Atlantic compliments of Ocean Weather. Quickscat satellite derived winds for the east
Atlantic: Cape Verde Islands to 5 degrees north Ascension Island and St Helena 24 hour forecast for Wind and direction in both the north and south Atlantic, thanks to the ocean modelling branch of NOAA. (forecasts use the AVN model). Also: 48 hour forecast, 72 hour forecast, 96 hour forecast. Wind
analysis from the University of Wisconsin showing surface, upper and jet
stream - or water vapor - winds. As well, there are charts showing wind
shear and upper level divergence. For the arm-chair sailor, the low-mid
level infra-red winds tell an awful lot about the sea state where the boats
are. Colour-coded arrows report wind strengths and direction at different
levels. Remember: Friction at the surface slows the wind down a bit,
so it will never be as strong at wave height as it shows on the 900hPa
chart. The University
of Nottingham offers geo-stationary satellite information showing the east
Atlantic and Europe/Africa. The Aviation Weather Centre offers these terrific flight level charts SIGWX) which show the position of jet streams over much of the globe (mostly Northern Hemisphere). Because upper level winds, like the jet stream, steer our weather systems, knowing where these winds are and how they are behaving helps us to understand whether systems are moving east to west quickly or whether they will stalling because of a kink in the pipe-line. More great reading: Read all about the Jacques Vabre race as well as its history at the official web site. We analyse how the Volvo fleet negotiated the North Atlantic and the Doldrums earlier this autumn. Playstation smashes the trans-Atlantic record by 44 hours by surfing the perfect front! Follow the Challenge Mondial Assistance through the official web site and get a preview of weather conditions on the route. Re-live the solo trans-Atlantic race of June 2000 and the Quebec to St Malo of last August. Catch up on all the past action of the recent Vendee Globe in our race archive. Re-live the action between the world's fastest multihulls in The Race Re-live the 2000 Sydney to Hobart yacht race! Break ice in the Ross Sea! |
