Altocumulus Sky

August 03, 2014

Altocumulus clouds 25.1.14

Photographer: Menashe Davidson
Summary Author: Menashe Davidson; Jim Foster
 
Shown above is a sky filled with altocumulus clouds taken at midday, January 25, 2014, in Rishon Lezion, Israel. The weather was quite fine this winter's day, with warm temperatures (68 F or 20 C) and low humidity. Based on the altitude of planes passing through this cloud deck on taking off and descending at nearby Tel Aviv Airport, I estimate the altocumulus were in the range of 2,500 m to 5000 m (8,200 ft – to 16,400 ft). At the high end of this range, convection increases and an altocumulus layer may thicken and begin to look less sheet-like. Individual clouds (cells) look puffier and slightly rounded. When this occurs an altocumulus layer then takes on a more structured appearance -- best seen here at lower center. This deck slowly drifted from south to north; within a little more than an hour the sky was completely clear.
 
Photo details: Camera Model: NIKON D80; Focal Length: 18.0mm (35mm equivalent: 27mm); Aperture: f/13.0; Exposure Time: 0.0050 s (1/200); ISO equiv: 100.