According to dictionary, overwhelming means:
very great or very strong; so powerful that you cannot resist it or decide how to react
Therefore it is clear that:
She has an overwhelming desire to achieve the goals.
Means that you cannot dissuade her from chasing her goals.
We faced overwhelming obstacles.
Means that we encountered some obstacles which we cannot overcome.
But I am not sure if it is correct and meaningful to say that:
In impoverished countries, poor people suffer from an overwhelming economic situation.
What does it mean to say "overwhelming situation"? Is it great like "overwhelming desire"? or it is disappointing like "overwhelming obstacles"?