The Atlantic Rally for Cruisers (ARC) is a well-known name among sailors: for many large and small charterers, the necessary transfer of their territory from their summer yachts to the wintry Caribbean is for many amateurs the easy entry into cruising. An Atlantic crossing is hardly easier to accomplish, in principle everything is organized, you just have to hire.
But whoever thinks that the ARC fleet with its more than a thousand sailors from 53 different countries has only one trip to go from Gran Canaria to St. Lucia in the Antilles Arch and only has to set sail to be driven by the trade wind, is wrong. By the way, if you understand german, you might want to read the german text version.
Not always easy: ARC start 2019 © ARC 2019 / WCC J. Mitchell
There are always disturbances
Certainly, there are many travel reports that seem to confirm the above expectations: The route is part of the so-called barefoot route, and with the end of hurricane period in early November, a more stable and secure. However, the last few years have repeatedly shown that disruptions can affect the actual trade wind field, which is expected from the start, because many books describe it, and can have a significant impact on the regatta field.
I have been watching the tracks since 2010 and analysed the respective weather conditions between start and finish.
ARC tracker of 2010 © Wetterwelt
In 2010 the Trade winds was temporarily disturbed
In 2010, the weather conditions at the start were typical: the Azores high ensured a stable trade wind that gained strength with every mile to the south. The boats drove a bit lower course compared to the great circle, the shortest way.
But after about ten days, a strong Atlantic depression showed, which caused the high-pressure zone at 30°N messed up. The low wind zone was shifted strongly to the south; and with it the wind. In the tracker it is easy to see how almost the entire fleet is moving south in order to see wind. Then it went on with a stable Trade wind.
ARC tracker of 2011 © Wetterwelt
The better wind was in the south
2011 was a year of very constant trade winds, with no disturbances. However, here was the better wind to find a little further south, so that went down to a few, all on the way towards Cape Verde and at about 20°N 30°W to St. Lucia bent.
In 2012, there were initially no particularities in the general weather situation, but the Trade winds were not fully developed. Due to a small-scale low that extended from West Africa in the direction of the Canary Islands and the Atlantic Ocean.
ARC tracker of 2012 © Wetterwelt
Thus, especially the fast boats drove a direct west course, isolated even in the northwest. So away from the goal. It was only when the low and its calm zone were resolved that the boats were able to set off towards the destination five days after the start with a better-built Trade wind.
High reached to England
A good long-term forecast was particularly important in 2013. At the start, the weather pattern shows an enormous north-south orientation. On the one hand from a low in the USA and further east also in the high. It extended to 30°N in east-west, but from 18°N over the Azores to Great Britain.
ARC tracker of 2013 © Wetterwelt
Due to the fact that this low wind zone was slowly moving eastwards, the Trade winds was largely absent. However, there was a small corridor used by the main field.