Clouds of the Day - Tuesday, May 12, 2020
/Altocumulus is one of ten principal cloud types. It occurs in the mid-levels of the atmosphere between the altitudes of 6,500 to 20,000 feet. Altocumulus occurs in a layer or patches of wavy, round, rolling, laminated shapes. The individual cloud elements when viewed more than 30 degrees above the horizon subtend an angle of 1 to 5 degrees. They appear smaller than cumulus that form in the low levels. They are made of small liquid cloud droplets or ice crystals. Even when temperatures are below freezing liquid droplets often occur in these clouds. This is known as supercooled water.
Today the sky has various types of altocumulus on display. Many of the different types are represented in the photos below. You will see individual cloud cells, wavy clouds and combinations of both shapes. In the first five photos the clouds look soft and fluffy. After that the sky changed. It transitioned from cellular to wavy altocumulus and finally cirrus.
Altocumulus (cells and wavy)
Altocumulus (cells and wavy)
Altocumulus (cells and wavy)
Altocumulus (cells and wavy)
Altocumulus (cells and waves)
Altocumulus (waves and small cells)
Altocumulus (waves and small cells)
Altocumulus (cellular)
During the afternoon the sky changed character - from altocumulus to cirrus. Cirrus are high flying clouds above 18,000 feet. Made of ice crystals, cirrus paint spectacular formations over blue sky. An official definition describes cirrus as a ringlet or curling locks of air. The cirrus in the photos play that part well. The bottom photo is strange. This thin line of cirrus may be man made, possibly due to an aircraft. The line of cirrus was in the sky for over an hour and moved from the western sky to the eastern horizon.
Cirrus
Cirrus
Cirrus (man made?)