Sunshine Coast sailor Jessica Watson is battling Antarctic gale force winds in the Southern Ocean as she continues her solo journey around the world.

The 16-year-old has been sailing for 78 days and is now preparing to round the notorious Cape Horn on the tip of South America.

Her mother Julie Watson says she is expecting swells of up to six metres and freezing gales of more than 35 knots.

"She was talking about hail and sleet and rain up topside, so it's pretty cold," she said.

The air temperature last night dropped below 7 degrees Celsius as Jessica battled 30-knot winds and a four-metre swell.

That is a far cry from the conditions she experienced on Saturday, when she blogged on her website that she "spent the morning doing jobs on deck and soaking in the lovely sunshine".

"Talk about a treat to have such lovely conditions!" she wrote.

Unfortunately for Jessica's fans, her website warns she will not be able to blog again until conditions improve.

Jessica set sail from Sydney Harbour on October 18 to begin her attempt to become the youngest person to sail solo and non-stop around the world without help.

Source:  Copied from ABC News