Cumulonimbus flammagenitus (cloud) column of a volcano. In 2002, various sensing instruments detected 17 distinct cumulonimbus flammageniti in North America alone. Alternate spellings and abbreviations for cumulonimbus flammagenitus that may be found in the literature include Cb-Fg, pyrocumulonimbus, pyro-cumulonimbus, pyroCb, pyro-Cb, pyrocb, and pyro-cb. The World Meteorological Organization does not recognize the cumulonimbus flammagenitus as a distinct cloud type, but instead classifies it simply as cumulonimbus. On 18 January 2003, a supercell thunderstorm formed from a cumulonimbus flammagenitus cloud associated with a severe wildfire, during the 2003 Canberra bushfires in Canberra, Australia. The supercell resulted in a large fire tornado, rated at EF3
The Cloud of Unknowing short word rather than a long one. A one-syllable word such as "God" or "love" is best. But choose one that is meaningful to you. Then fix it in your mind so that it will remain there come what may. This word will be your defence in conflict and in peace. Use it to beat upon the cloud of darkness above you and to subdue all distractions, consigning them to the "cloud of forgetting" beneath you. Editions of related texts include The Cloud of Unknowing The Cloud of Unknowing (Middle English: "The Cloude of Unknowyng") is an anonymous work of