WX Rules: Avoiding the Azores High
The primary weather feature in any west-to-east Atlantic crossing is the Azores high, which in spring and summer is normally established near 40 degrees north latitude. The traditional sailing instructions are to route north over the top of the high, without going so far north as to get caught in the low-pressure systems marching across the Atlantic to Europe.
This year as the ARC Europe fleet departed Bermuda, the Azores high was centered abnormally far north, near 46 degrees, blanketing the middle latitudes with light and variable winds. But the long-range forecast was for the high to quickly drift south. On Kinship, the Saga 43 that I skippered, we aimed north, looking to route round the top of the high as it moved south. By the fifth day out we’d already reached the latitude of the Azores, 38 degrees 30 minutes, but continued ENE, aiming for 40 degrees. We were well positioned in the slot between the high to our east and lows moving off Nova Scotia.
The first low passed us to the north, and with it we experienced the strongest winds of the crossing, from the west gusting into the upper 30s. As the cold front trailing below the low went through, the wind abruptly shifted to the west-northwest and eased. The front brought rain, but with the wind shift the sky cleared and the stars came out. The air was noticeably drier.
This pattern continued for the duration of the crossing. We sailed along the top of the high with the wind oscillating between southwest and northwest as the lows passed to the north. Only once, for perhaps half a day, was the wind forward of the beam.
The boats to the south of us and slightly west had lighter air and recorded more engine hours. Talisman II, another Saga 43, sailed the southerly rhumbline route and finished over a day behind Kinship, recording 50 engine hours to our 22. Conversely, the bigger yachts south and farther east were able to stay ahead of the high as it moved south and made very fast passages.
The boats toward the back of the fleet experienced the worst weather. Despite the northerly position of the Azores high as the fleet left Bermuda, it ended up farther south than normal, as had been the pattern over the spring. The last low to overtake the fleet also tracked south and caught the slower boats as they approached Horta. Chiscos, a Warrior 40, saw sustained winds over 40 knots, and First Edition III, a Catalina 42, was knocked down by a rogue wave.
In the end the boats that made the fastest passages were not the ones that went north or south, but the ones that committed to either route and sailed a steady course. It was the boats
that never made up their minds as to which way to head that took the longest time to cross.
Read about the 2012 ARC Europe rally here.
Image courtesy of Andy Schell