ADELAIDE, Australia -- The first two stages of the Tour Down Under cycle race, the opening event of the 2019 professional World Tour, have been shortened after forecasters warned of extreme heat and high winds in South Australia.

The Tour, which has attracted the world's top professional teams and riders, including three-time world champion Peter Sagan, begins Tuesday with the first of six stages in the hilly, wine-growing regions around the city of Adelaide.

Organizers announced Sunday that the second stage through the Barossa Valley, famous for its wines, would be shortened because temperatures were expected to hit 40 degrees. On Monday the decision was made to also trim the first stage, removing a scheduled loop around the finish at Port Adelaide, because of forecast high winds.

Race director Mike Turtur said Tuesday's stage "will be brutal" in possible blast furnace heat, fanned by the wind. Conditions were likely to stretch out the field, raising safety issues for some riders.

The 2018 edition took place in the second-hottest conditions in the race's 21-year history, behind record temperatures set in 2006.