In a food processor or blender, combine the mayonnaise, sour cream, parsley, dill, chives, Worcestershire sauce, black pepper, vinegar, paprika, salt, cayenne, hot sauce, chipotle peppers and garlic. Add the buttermilk to the desired consistency and blend. Chill for a couple of hours before serving, thinning with more buttermilk if needed.
Serve the carrots, celery and cucumbers with the dip.