Primed to burn: What's behind the intense, sudden fires burning across New South Wales and Tasmania?

Summary

Dozens of bushfires have erupted across New South Wales and Tasmania, resulting in the tragic death of a firefighter and the destruction of multiple homes, with 16 in Koolewong and 19 in Dolphin Sands reported lost. According to Phys.org, the fires have spread as far as the mid-north coast of New South Wales and Tasmania's east coast.