A chain of wild brushfires burning to the north, south and west of Sydney have the potential to converge into an enormous "megafire" that could threaten the lives and property of thousands of Australians in the state of New South Wales.

The weather in the region is not predicted to be cooperative in the coming days, which will lead to conditions enabling the fire system to expand, the Sydney Morning Herald (SMH) reported.

Wednesday is predicted to be the worst day of weather yet for fire crews responding to the scene. Temperatures are expected to be around 100 degrees Fahrenheit and 60 mph winds will make stopping the fires from merging into a megafire difficult.

But Rural Fire Service inspector Andrew Luke said the goal is to keep the fires from merging, according to the Australian Broadcasting Corporation, which is live-blogging the event.

''This will be as bad as it gets,'' Rural Fire Service Commissioner Shane Fitzsimmons told the SMH. ''On days like [this], there's a very real potential for more loss of homes and life.''

Fire crews -- a team of at least 1,500, reported to be one of the largest ever assembled to battle a blaze in the region's history -- were preparing for Wednesday, which is expected to be hotter, drier and windier than weekend forecasts predicted.

There are four major fires burning in New South Wales, along with 53 others, the SMH reported, adding that 13 of the blazes are uncontained.

According to the Daily Mail, the merging of the fires into one massive blaze could also trigger a weather system known as "fire clouds," which are fueled by the heat of the conflagration and can produce devastating lightning storms.

Fire clouds are created by the hot air that rises in a column from the fire on the ground. Cool air rushes in to take the place of the rising warm air, but if conditions are right, the smoke, heat and any water vapor present will continue to rise, forming a pyrocumulous cloud that can generate lighting and thunderstorms that may ignite more fires further downwind of the of original fire.

So far, only one death has been linked to the fire -- a man who reportedly suffered a heart attack as he defended his home from an encroaching blaze.

The fires are mostly affecting sparsely populated areas in New South Wales, but in Sydney, home to 4.6 million people, the effects of the fire are inescapable.

Sydney is reportedly blanketed in smoke from the fires. NPR correspondent Stuart Cohen said the aroma of smoke can be smelled from within buildings and that Sydney health officials expect a surge in cases of respiratory problems.