Looking at some of my study notes reminded me today, that not all network outages are man made. Elemental power is sometimes at work.
Air:
High Density winds and tornados
http://www.goes.noaa.gov/WINDS/index.html
Earth:
Earth quake Seismic Monitor
http://www.iris.edu/seismon/
Fire:
Fire warnings
http://www.spc.noaa.gov/products/fire_wx/
Water:
Huricanne watch
http://www.nhc.noaa.gov/
Tsunami Warning Center
http://www.prh.noaa.gov/ptwc/
Space:
Meteor showers, solar flares, auroras, and near-Earth asteroids
http://www.spaceweather.com/ and http://ssd.jpl.nasa.gov/
An interesting site is downforeveryoneorjustme.com when having trouble with a url.