(Wine-Searcher) - While northern wines are overwintering in the cellars, some Southern Hemisphere wineries are getting started on the 2015 vintage.

Parts of Australia and South Africa have begun the 2015 grape harvest, with ideal conditions leading to earlier-than-usual starts.

Barossa Grape & Wine Association communications manager Baron Barbara Storey said this year the grapes were already being picked, despite the actual harvest-start celebration being scheduled for next week.

"Vintage is already in full-swing because of the great ripening season and the heatwave we've just had," she said.

"In the Barossa, as well as many other wine regions, people are up all hours of the night and particularly with this weather they have to make sure they get the grapes in while they're cool and keep them cool."

Some Barossa growers were expecting a smaller-than-usual Shiraz crop, after frosts hit the region in October. The full extent of the damage only became apparent at harvest. Nigel Blieschke, viticulturist with Peter Lehman wines, said the winery was looking at a lighter crop.

"Probably across the board we crush nearly 10,000 tonnes and we probably lost about 1500 tonnes," he said. "I think we'll be able to cover some of that with extra purchases, but there's not going to be a lot of excess stock anywhere in the Barossa after that frost."

Harvest is also underway in Western Australia's Margaret River and Geographe regions, with one winemaker saying it is the earliest he has ever picked fruit. Grape yields were slightly below average this year, but quality looked good, the Australian Broadcasting Corporation reported.

The chief winemaker for Geographe's Willow Bridge Estate, Simon Burnell, said a burst of unseasonably warm weather last August set the fruit on track for an early pick.

"February 6 is certainly the earliest we've ever started crushing fruit," he said. "Our first pick of fruit from our own vineyard is coming in next week, which will definitely be the earliest off our own vineyard ever as well."

In New South Wales, one of the Canberra wine region's trailblazers has described 2015 as "a cracker of a season never seen before".

The harvest of grapes in the Murrumbateman area in New South Wales, west of Canberra, has started several weeks earlier than usual with an abundance of fruit. Ken Helm is producing his 39th vintage and "all the right boxes have been ticked" after favorable weather over the last few months. He said the grapes were in great condition.

Meanwhile, a twister badly damaged vines and an equipment shed at a vineyard in the Hunter Valley.

Footage of the twister at Keith Tulloch Wines in Pokolbin showed wind blasting through parts of the property on Sunday afternoon. No one was injured, although about 100 vines and an equipment shed were destroyed.

Cellar door staff first realized something was headed their way when they were pelted with fruit on the second floor of the winery.

"They looked up and they saw a spiral vortex, which then started to touch down into the vineyard on the other side of the winery," spokesman Alisdair Tulloch said.

Across the Indian Ocean, South Africa has had the its earliest harvest of the century, with some Swartland wineries having very early finishes to the season. Adi Badenhorst finished picking before Valentine's Day, while Spice Route Winery was also crushing grapes by the end of January.

Growers in Stellenbosch were expecting to get all fruit in by end of this month and overall the harvest looks good, if slightly smaller than last year.