Updating ValidationSummary Via Asynchronously - ASP.NET MVC

Question

In my controller, if the modelstate is invalid

if (!ModelState.IsValid)
      return View();

I'd like to update the ValidationMessage but not have to repost the View. Seems like a desirable concept with validation messages. I'm using DataAnnotations as well that uses <% Html.EnableClientValidation(); %> but it still posts to the controller and I have to perform this check. Any suggested implementations?