Global Challenge crews are preparing for another interesting weather system as they head down the coast of Brazil.

The current situation shows a high-pressure system developing over the land 200 miles south-east of Uruguay, giving crews plenty to think about on their final stretch to Leg 1 finish.

According to Cal Tomlinson – Sailing Manager at Challenge Business the current weather system is fairly unusual, and very unstable with a series of high-pressure systems rolling in. Commenting on the situation Tomlinson said: “The weather here is usually dominated by the Trade Winds and settles for a couple of days at a time until about halfway down the coast before it becomes full of anomalies. This time however, the crews have only sailed a brief area, right at the beginning of the proximity to South America, where they’ve been able to count on Trades.”

The last few days have been squally which is the result of the high-pressure systems colliding. The winds have been shifty sometimes 180 degrees as the yachts have sailed through the systems. Barclays Adventurer still retains a 21-mile lead but by heading too far offshore Samsung has lost her second to Vaio who’s currently tracking Barclays.

Although the wind is currently from the south-east it will back initially to north-east and then north-west, and fill in within the next 36 hours. The wind is not expected to reach much above 25kts but it will become squally as the wind tracks over the land. Tomlinson added: “There’s also another little high south of the River Plate but I’m not sure if that’s going to develop or not.”

With the wind fairly predicable over the next couple of days there should be little in the way of place changes but once the fleet rounds the waypoint, positioned south of Punta del Este 150 miles from the finish, Tomlinson believes the fleet will settle into more of a regatta-type race. Chatting about tactics, Tomlinson concluded: “With the wind from this direction my call would be to stick to the rhumb line.”

Interestingly, those who diverted offshore away from the line such as Matt Riddell on Samsung are now on their way back in but can they do enough to make up for their lost ground with just under four days to go?

The estimated time of arrival for the first yachts due into Buenos Aires is Thursday night/Friday morning.

Positions at 1344 today

Barclays Adventurer 610 miles to finish

VAIO 633 miles to finish

Samsung 658 miles to finish

BG SPIRIT 681 miles to finish

BP Explorer 692 miles to finish

Spirit of Sark 729 miles to finish

SAIC La Jolla 782 miles to finish

Imagine It. Done 879 miles to finish

Team Stelmar 891 miles to finish

Me to You 902 miles to finish

Pindar 995 miles to finish

Team Save the Children 1,313 miles to finish