Tornado Warning in Google Results

Interesting, helpful example for a part of the knowledge graph:

The overview maps on google.org where very helpful, too, although I did not check for their timeliness - which is key.
I did not take a screenshot of the map, but it also has a good collection of additional links and info (and alerts active at the time looking at it ).

The map is also highly configurable (screen showing only a part of the options). Very interesting - it looks like a high level mashup of various sources with maps.