Bring a large pot of salted water to a boil. Add potatoes; cook until tender but still firm, about 15 minutes. Drain, and set aside to cool.
In a large bowl, combine the potatoes and chopped eggs.
Mix together the yogurt, mayonnaise, green onions, mustard, dill weed and garlic powder. Pour dressing over potatoes and eggs; toss and chill until ready to serve.
