Advertisements

Arcus cloud from a thunderstorm

click to enlarge - image by Scott Gates

Thunderstorm in Summer 2010, Waconia, MN. Backlit by the sun, note the shelf or “arcus” cloud.

From Wikipedia: An arcus cloud is a low, horizontal cloud formation associated with the leading edge of thunderstorm outflow, or outflows of cold air from sea breezes or cold fronts in the absence of thunderstorms.

A shelf cloud is attached to the base of the parent cloud (usually a thunderstorm). Rising cloud motion often can be seen in the leading (outer) part of the shelf cloud, while the underside often appears turbulent and wind-torn. Cool, sinking air from a storm cloud’s downdraft spreads out across the surface with the leading edge called a gust front. This outflow undercuts warm air being drawn into the storm’s updraft. As the cool air lifts the warm moist air, water condenses creating a cloud which often rolls with the different winds above and below

Advertisements

Posted on May 4, 2011, in Clouds, Thunderstorms, turbulent or shear and tagged , . Bookmark the permalink. 2 Comments.

  1. This is not an arcus cloud. This is the rotating mesocyclone of a supercell in which warm air ascends and rotates as a result of strong deep and mid layer sheer. The dynamics are completely opposite to that of a gust front . Varying humidity levels within the air column combined with shear produce beautifully sculpted and striated updrafts such as this one.

  2. Quality content is the crucial to interest the users to visit
    the site, that’s what this site is providing.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: