Better head there early. Photo: Dallas Kilponen - Sydney Morning Herald

Better head there early. Photo: Dallas Kilponen

Sydneysiders are in for another scorching day with weather forecasters lifting their prediction of heat for the day.

The Bureau of Meteorology has raised its forecast for Sydney to 39 degrees from a mid-30s target issued yesterday.

• Baptism of bushfire


• Regions 'primed to go'

Penrith, just 50 kilometres inland, may hit 45 degrees according to the bureau, while suburban Bankstown may reach 41-42 degrees, Weatherzone said. Regions in the state’s far north-west of the state, such as Bourke, are forecast to endure 47 degrees.

Temperature peaks for the Sydney region will depend on how much westerly winds hold back cooler sea breezes, said Drew Casper-Richardson, a meteorologist at Weatherzone.

The extreme heat will make it another tough day for firefighters. Authorities have declared a total fire ban across the state for a second day in a row.

The Rural Fire Service was last night battling 98 fires, 16 of which are yet to be contained.

Today’s expected strong westerly winds are expected to add to the bushfire risk, with three fires posing the greatest concern - the Deans Gap fire in the Shoalhaven, the Cobbler Road fire near Yass, and the Yarrabin fire in the Cooma-Monaro region.

‘‘The winds will generally be weaker than Tuesday,’’ Mr Casper-Richardson said.

Dome of heat

Central Australia’s giant heat cell is showing little sign of breaking up, with only ‘‘some indications’’ that it may start to cool off in ‘‘about a week’s time’’, he said.

The hottest region in the country on Saturday is likely to be the north-east of South Australia, with Moomba headed for as high as 49 degrees, with a similar peak for Sunday. ‘‘There’s an outside chance of 50,’’ Mr Casper-Richardson said.

Tropical Cyclone Narelle continues to skirt the north-western coast of WA, and will gradually weaken, he said. Wind gusts at Karratha have so far reached a maximum of 83 kilometres an hour.

While the cyclone is bring cloud and some moisture over the continent, it ‘‘will take more to disperse the heat over the inland,’’ Mr Cooper-Richardson said.

So far, most of the cool changes coming over southern regions have brought little rain, with the heat floating over central Australia contributing to drier conditions in the south-east, he said.

With AAP