In a large pot of salted water, boil the potatoes until tender. Drain and place in a large mixing bowl. Cool slightly.
Drizzle the vinegar over the warm potatoes and allow that to soak in. Stir in the mayonnaise and distribute throughout. Season the potatoes with the salt, dill, pepper, and tarragon. Allow the salad to cool.
Add the sour cream, celery, and scallions. Adjust seasonings. Chill under ready to serve.
Though you can serve the salad warm, it’s nice to let it chill several hours before serving.