A brief respite from the heavy going will give way to high winds and huge seas from a low pressure system moving down from the north.
"A secondary low is coming down the coast and will kick our butts about 250 miles from the Horn," said PUMA skipper Ken Read.
Leaders Groupama sailing team are expected to round Cape Horn around 1200 UTC on Friday, followed closely by PUMA.
Despite enjoying a lead of around 52 nm at 1300 UTC today the French team are ever wary of their rivals.
"We can really feel the pressure from PUMA," said helmsman Thomas Coville, preparing for his ninth rounding of Cape Horn. "They need to stay with us, and we need to answer them. We have to show we can be faster.
"There is a psychological game going on at each position report. We are playing poker with PUMA for first and second."
Read says the cat and mouse game is one the PUMA crew know all too well and are happy to play.
"When it is full-on and you need to back off a bit you use your sked to say to the other guy, 'Don't worry, we aren't going to push,'" Read said. "Of course, then one of us pulls the trigger to sail full speed immediately after the sked in order to hopefully maximise the time back up to speed."
Meanwhile, third-placed Team Telefónica continued at decent speed towards Ushuaia, where their shore team await to carry out repairs.
"We are sailing pretty fast but the pity is that we could go faster," media crewmember Diego Fructuoso said. "Pepe (Ribes, boat captain) has done a great job with the repair, ensuring that we will not have any problems until reaching port.
"On the other hand, the logistics are very complex and the effort from Horacio Carabelli (shore team manager) effort has been incredible. From the boat we told them what we needed and he has done everything and awaits us at Ushuaia with a team ready to repair the boat as quickly as possible."
CAMPER with Emirates Team New Zealand, in fourth, celebrated reaching 1,500 miles to go to Puerto Montt in Chile where they will stop to repair bow damage.
"We're all still trying to get the boat to Chile as fast and as safely as we can so we can have a quick turnaround and get to Brazil as quickly as possible," said co-skipper Stu Bannatyne.
At 13:00 UTC today Abu Dhabi Ocean racing remained in fifth place 1,448 nm off the lead.
1.) Team Telefónica 122 points
2.) Groupama sailing team 107 points
3.) CAMPER with Emirates Team New Zealand 104 points
4.) Puma Ocean Racing powered by BERG 83 points
5.) Abu Dhabi Ocean Racing 55 points
6.) Team Sanya 25 points
Volvo Ocean Race website - www.volvooceanrace.org