Cinematic 4K 60 fps. Cirrus is a genus of atmospheric cloud generally characterized by thin, wispy strands, giving the type its name from the Latin word cirrus meaning a ringlet or curling lock of hair. Time lapse forest mountain ridge hill woods trees pine forests blue dark sky white green spring summer autumn morning nature natural afternoon wind air slope dome mount temperate regions deposition tropical circus cyclones weather conditions ice crystals jet stream main layer cirrostratus clouds tufts pattern wood tree woodland boreal dense vegetation land cover conifer beech broadleaf forestry hurst sunny partly cloudy clear open sylvan grove plant plants subtropical ecoregion taiga 3840X2160 UHD.