Today marked the completion of many of the missing pieces. Entering incorrect Zip Code / City information is now handled properly, as are ambiguous locations (you'll get a list to pick from). National Weather Service warnings, watches, and advisories will now display on the home page here. The Forecast Details now also contains Past Weather. You can create a PDF for your location with the forecast on it. The weather pages are cached for better server performance and the shading and colors have been adjusted.
You may need to re-select your location, as I moved from my own cookie storage to the built-in storage. This will only simplify things down the road. If you have any comments on the new weather system, please let me know.