A is a Japanese expression used to describe a short, localized
downpour of over 100 mm per hour of rain caused by the unpredictable formation of a
cumulonimbus cloud
Cumulonimbus (from Latin ''cumulus'', "heaped" and ''nimbus'', "rainstorm") is a dense, towering vertical cloud, typically forming from water vapor condensing in the lower troposphere that builds upward carried by powerful buoyant air currents. ...
. The term is often used by the Japanese media in reporting such events, but does not have an official meaning nor is it used by the
Japan Meteorological Agency
The , abbreviated JMA, is an agency of the Ministry of Land, Infrastructure, Transport and Tourism. It is charged with gathering and providing results for the public in Japan that are obtained from data based on daily scientific observation an ...
.
History of usage
The first example of the term being used was by the ''
Yomiuri Shimbun
The (lit. ''Reading-selling Newspaper'' or ''Selling by Reading Newspaper'') is a Japanese newspaper published in Tokyo, Osaka, Fukuoka, and other major Japanese cities. It is one of the five major newspapers in Japan; the other four are ...
'' in August 1969. It carries the same meaning as the term , but is differentiated by the added feature of being difficult to forecast, hence the reference to the aspect of
ambush
An ambush is a long-established military tactic in which a combatant uses an advantage of concealment or the element of surprise to attack unsuspecting enemy combatants from concealed positions, such as among dense underbrush or behind mo ...
associated with the term
guerrilla warfare. Neither "guerrilla rainstorm" nor "cloudburst" is a defined term used by the meteorological agency, which instead uses the term .
Usage of the term spread in the private media from 2006.
See also
*
Cloudburst
A cloudburst is an extreme amount of precipitation in a short period of time, sometimes accompanied by hail and thunder, which is capable of creating flood conditions. Cloudbursts can quickly dump large amounts of water, e.g. 25 mm of pre ...
References
{{reflist
External links
High-resolution Precipitation Nowcasts, predictions with a spatial resolution of 250 m(
Japan Meteorological Agency
The , abbreviated JMA, is an agency of the Ministry of Land, Infrastructure, Transport and Tourism. It is charged with gathering and providing results for the public in Japan that are obtained from data based on daily scientific observation an ...
)
Climate of Japan
Japanese words and phrases
Rain