Severe Weather Growler is a weather alert monitoring service for Growl. This application should be able to send growl notifications to any Growl server.
This program polls the National Weather Service every 90 seconds to see if any new alerts have been posted. If so, you will be notified. Note that each alert type at the NWS is a different notification type within Growl. Therefore, you can set the type of notification for each type of alert.