Well much has to do with the size and length of the elements as compared to the boom. In some cases, the boom can be MUCH longer and heavier than the eles. Or, like a 2 el 40M full-size or 2 el 75M full-size, an occassional design may have the boom of less wind resitance than the eles. The only way to really find out is to let it swing in the wind and see how it "weather-vanes". But this is impractical.
In your case as described, I would agree with Frank and point the array elements into the wind.
At one time I had a broken rotator on my 30' boom 7el 6M Yagi and got to watch it swing like a weather vane for a few months. It always sat with the elements broadside to the wind.
Now some think that becuz the eles all line up in the horiz plane that the wind sees JUST one element in effective wind loading. This is not entirely true since the wind can come from many different vertical directions in gusts, so at times you may have the acummulative effect of many elements in wind loading.
In Pacific coast Calif and Scotland, the guys lose Yagi antennas to broken booms because of severe updrafts that want to flip the antenna over. Just imagine a big Yagi that is overhead trussed for gravity with no under-trussing in a situation like this. This happens to guys on cliffs that have severe wind shear from updrafts on the hills, etc.
But generally, the rule is that whenever there is a Nor'easter coming, face your Yagi into the wind like a ship...