Volume 56, Number 3 December 2012 Photo by Denice Drass
Volume 56, Number 3 December 2012 Photo by Denice Drass
Volume 56, Number 3 December 2012 Photo by Denice Drass
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ArCUS Clouds<br />
<strong>December</strong> <strong>2012</strong> ~ Mariners Weather Log<br />
14<br />
ArCUS Clouds<br />
Chief Mate, Cezary Poninski , of the M/V OCEAN GIANT<br />
took these impressive photos of an arcus cloud on April 9th<br />
<strong>2012</strong>, in the eastern part of the Black Sea. Thunderstorms<br />
are sometimes accompanied <strong>by</strong> an arcus cloud. There are<br />
two types of arcus clouds; a shelf cloud and a roll cloud.<br />
These types of clouds are usually associated with the leading<br />
edge of a thunderstorm outflow. Cold air rushes out of a<br />
downdraft and lifts warmer air in front of the storm complex<br />
up to condensation level, making both a fascinating and<br />
menacing sight while it is approaching at high velocity. In<br />
the absence of thunderstorms, this can be formed <strong>by</strong> outflows<br />
of cold air from a sea breeze. The photographs taken <strong>by</strong> C/M<br />
Poninski are of the “roll type” variety. A low, horizontal,<br />
tube shaped , and a relatively rare type of arcus cloud. The<br />
roll cloud, are a solitary wave called a “soliton”, which is a<br />
wave that has a single crest and moves without changing<br />
shape or speed.<br />
<strong>Photo</strong>s <strong>by</strong> Cezary Poninski<br />
Pictured is Bosun Joseph Casalino
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