Snowies seem to have random feeding behavior, but if you spend enough time watching an individual you learn to pick up its patterns. That being said, those observations can easily be ruined when the owl is disturbed, they will completely change their behavior when disturbed by people.
I'm sure we have just as much beach and dunes for them to hunt on as the east coast.
Starting in November I go to the beach to look for owls. Once a bird has arrived, I do not immediately go and photograph it. I observe the bird from over half a mile away for several days picking up its flight patterns and favorite perches. This time also allows it to hunt without being disturbed by people. This can be quite boring, but I enjoy learning about bird behavior.
Snowies will always have several favorite perches that they shift every couple of hours. And typically they are most active in the mornings. Once birders, photographers, or curious people start to push the owls around, they tend to move their hunting into the late evening around dusk.
I always draw a perch map of the surrounding perches and tally every time an owl lands on one. The perch that has the most tallies, and the best photographically, is chosen as my blind perch. The third or fourth day I will go in at midnight and dig a pit blind, I'll sleep in my car and walk in an hour before sunrise. It works