Cause
I believe the Flight Operations department must take major responsibility for this accident. They knew what the weather was at ORK before departure. Given that they could have (taking into account the crews in-experience) delayed the flight until the weather was improving or as they also knew there were only 12 souls on board put more fuel on to give the captain a chance of diverting to well outside the area. By the looks of things they chose to take none of these choices but to take the bean counters way.
Granted in order to make a profit it is prudent to do things a certain way but when you know it is going to be difficult you don't tie your crew's hand behind their backs. This is going to cost a lot more than a delay of a couple of hours or the cost of a couple of hours fuel.
So lets not be too quick to blame the pilots perhaps flight ops and the management need to be re-educated. Flight ops gave the go ahead for the flight knowing the crew's experience.