Pulse the grapes, scallions, cucumbers, garlic, parsley and avocado in a food processor until combined. Add the olive oil and white wine vinegar and pulse again until blended. Add 1/4 cup ice water and pulse again. Add more water if it is not at your desired consistency.
Season the gazpacho with 1 teaspoon salt and 1/4 teaspoon pepper. Refrigerate until chilled, about 1 hour. Serve topped with the toasted almonds.