NOAA provides a wealth of GIS data, including updates of its weather predictions.
Here are some useful links:
- The NWS GIS Data Portal, where you can download kml and shapefiles. From there, you can go to:
- The NWS Web Services Page, where you can get the connection information for live mapping service that can be used in ArcMap. Also:
- The nowCoast Information Depot, which has more metadata than you would ever need. It looks like they are using ArcIMS, which still works just fine!