A strong low pressure system over Canada.
NASA
2001-08-12
<a rel="nofollow" class="external free" href="http://rapidfire.sci.gsfc.nasa.gov/gallery/?2001224-0812/Canada.A2001224.1645.2km.jpg">http://rapidfire.sci.gsfc.nasa.gov/gallery/?2001224-0812/Canada.A2001224.1645.2km.jpg</a>