Dark Stripes
Rather narrow dark stripes in WV images, representing dry sinking air along the cyclonic side of a jet stream.
One of the main features in WV images are rather narrow Dark Stripes lying along the cyclonic side of bright bands and fibres. Typically they occur on the cyclonic side of a jet axis, to the rear of Cold Fronts and Occlusions, and along the leading edge of Warm Fronts. The Dark Stripe represents sinking dry air which can be of stratospheric origin. As such, the stripe can be used as an indication of cloud dissipation from above or to indicate possible unstable development at the boundary between dry and moist air. Dark Stripes in WV images are especially useful if they are combined with relative streams where they can frequently be found associated with dry intrusions as well as with isentropic potential vorticity.