Credit & Copyright: Daniela Mirner Eberl
Explanation:
What kind of cloud is this?
A roll cloud.
These rare long clouds may form near advancing cold fronts.
In particular, a downdraft from an advancing storm front can cause moist warm air
to rise, cool below its dew point, and so form
a cloud.
When this happens uniformly along an extended front, a
roll cloud may form.
Roll clouds
may actually have air circulating along the long horizontal axis of the cloud.
A roll cloud is not thought to be able to morph into a
tornado.
Unlike a similar
shelf cloud,
a roll cloud, a type of
Arcus cloud,
is completely detached from their parent
cumulonimbus cloud.
Pictured
above, a
roll cloud extends far into the distance in 2009 January
above Las Olas Beach in
Maldonado,
Uruguay.
Note: An
APOD editor will review astronomy images of 2009,
hosted by the Amateur Astronomers Association of New York on Friday,
January 8 at the American Museum of Natural History, NYC.
January February March April May June July August September October November December |
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NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: Roll cloud - weather
Publications with words: Roll cloud - weather
See also: