This is the result of a ghast fireball in Minecraft, summoned in with a custom explosion power using a command. The rays cast by the explosion are clearly visible in the ground because the explosion power of this particular fireball was set hundreds of times higher than that of a normal ghast fireball, so it spreads out a great deal more. This video by JL2579 and this video by WubbiConcepts explain this in much greater detail.
Another explosion in Blender, polished with paint.net. A sphere is broken into particles, which are used as the smoke flow object, and create the fireballs. The base resolution is 30 and high resolution is set to 3. This time the particles emit smoke and fire instead of just smoke. The scene is lit with a sun lamp.