photo #4758558

The morning after a storm had blown through, Carol Haufler (Cloud Appreciation Society Member 56,187) stepped outside to find this tapestry of interwoven Cirrus clouds over Philadelphia, Pennsylvania, US. The parallel filaments of the high cloud are known as fibratus, and when they appear in distinctly different orientations like this, they suggest the cloud has actually formed at more than one level in the atmosphere, which is described as duplicatus. It is only really possible to notice Cirrus fibratus duplicatus from the ground when the winds flow in very different directions at the two levels so they knit the cloud filaments into opposing weaves