A strong cold front will sweep over much of Australia over the weekend, potentially causing the largest outbreak of frigid conditions in 15 years, the Bureau of Meteorology says.

The likelihood of snow falling over the ranges all the way up into Queensland also has emergency services warning motorists and those planning outdoor activities such as skiing or camping to "plan carefully for the cold conditions".

Blair Trewin, senior climatologist with the bureau, said the last time Australia had such a large northward spread of snowfall was in May 2000.

"On the current forecasts, [the coming cold outbreak] won't be quite as significant but it may be in a broadscale sense," Dr Trewin said.