What follows immediately after the onset of visible flames in a potential backdraft situation?

When visible flames appear in a potential backdraft situation, it indicates that the fire has reached a critical point where there is an explosive release of energy. This is known as a rapid outburst of combustion. In a backdraft scenario, the environment inside the structure becomes highly charged with combustible gases due to the lack of oxygen for sustained combustion.

Once these gases have reached the right mixture and ignition source presents itself, the sudden appearance of flames denotes that a significant combustion event is about to occur. This can lead to an explosive force capable of causing extensive damage and injury, making it imperative for firefighters to recognize these signs and take appropriate safety measures.

The other choices present scenarios that may be possible in certain fire dynamics but are not directly related to what happens immediately after visible flames emerge in a backdraft situation. Understanding this phenomenon aids in fireground tactics and enhances safety protocols for responding teams.