When can you override a GPWS warning?
You should never ignore a GPWS warning, especially EGPWS/TAWS.
Although you may think that you are safe, most terrain encounters are due to human errors (yours or someone else) in misunderstanding the situation / location.
Always commence a climb and reassess the situation at a safe altitude, not just when the warning stops.
Remember that nothing is ‘so obvious’ in aviation as the scene of a CFIT accident.