File:Cloud streets off Alaska and the Aleutian Islands (MODIS 2015-03-18).jpg

English: Wintery winds blowing icy air over the Pacific Ocean created beautiful patterns in the clouds in mid-March, 2015. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite captured this true-color image of the scene on March 12 as it passed overhead.

Sea ice sits in the Bering Strait, west of Alaska�s coast. Many of the parallel rows of clouds begin off the edge of the sea ice, while others begin off the coast of the Aleutian Islands, and a few from the edge of the Alaskan mainland. Most of the land is covered in bright white snow and ice. The clouds are also white, but tend to appear slightly grayer than the highly-reflective ice and snow. When it is important to distinguish ice and snow from cloud, other MODIS band combinations (false color) or thermal images created from MODIS temperature sensors are more generally more effective than true-color images. In this case, the location and linear arrangement of the clouds make them visibly different than solid ice and snow.

The parallel rows of stratocumulus clouds are known as �cloud streets�, and are a common formation in this location in the colder months. Severely dry, cold air blowing over moister, relatively warmer water creates conditions favorable for cloud formation over the ocean. The clouds streets align parallel with the track of strongly blowing wind. Where the wind is weaker, such as far out over the ocean, the tight rows begin to widen and soon lose their neatly defined parallel formation.